719

719 is a prime number. It is a Sophie Germain prime because 2 x 719 + 1 = 1439, also a prime.

719 is a number that can be expressed as both a factorial prime (6! - 1) and as an abundant number less 1.

719 is the number of rooted trees with 12 vertices.

719 is a right-truncatable prime number: 719, 71, and 7 are all primes.

719, 197, and 971 are all primes.

The hour and second hands of an analog clock align 719 times every twelve hours.

Source: Prime Curios!