309693 has 4 divisors (see below), whose sum is σ = 412928. Its totient is φ = 206460.

The previous prime is 309677. The next prime is 309707. The reversal of 309693 is 396903.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is not a de Polignac number, because 309693 - 2⁴ = 309677 is a prime.

It is a D-number.

It is the 557-th Hogben number.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 309693.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (309623) by changing a digit.

It is a nontrivial repunit in base 556.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 51613 + ... + 51618.

It is an arithmetic number, because the mean of its divisors is an integer number (103232).

2³⁰⁹⁶⁹³ is an apocalyptic number.

It is an amenable number.

309693 is a deficient number, since it is larger than the sum of its proper divisors (103235).

309693 is a wasteful number, since it uses less digits than its factorization.

309693 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 103234.

The product of its (nonzero) digits is 4374, while the sum is 30.

The square root of 309693 is about 556.5006738540. The cubic root of 309693 is about 67.6566457965.

The spelling of 309693 in words is "three hundred nine thousand, six hundred ninety-three".