350

350 = 2 x 5 x 5 x 7.

350 is a divisor of 99² - 1.

350 is 1010 in base 7. It is 252 in base 12.

350 is a Stirling number of the second kind S(7,4) (A008277).

1 + 350¹ + 350² + 350³ + 350⁴ + 350⁵ + 350⁶ is a prime (A100330).

The sum of the first 350 primes (379667) is a prime (A013916).

Source: On-Line Encyclopedia of Integer Sequences