309905436 has 12 divisors (see below), whose sum is σ = 723112712. Its totient is φ = 103301808.

The previous prime is 309905417. The next prime is 309905459. The reversal of 309905436 is 634509903.

It is a tau number, because it is divible by the number of its divisors (12).

It is a hoax number, since the sum of its digits (39) coincides with the sum of the digits of its distinct prime factors.

It is a junction number, because it is equal to n+sod(n) for n = 309905394 and 309905403.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 12912715 + ... + 12912738.

Almost surely, 2^309905436 is an apocalyptic number.

It is an amenable number.

309905436 is an abundant number, since it is smaller than the sum of its proper divisors (413207276).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

309905436 is a wasteful number, since it uses less digits than its factorization.

309905436 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 25825460 (or 25825458 counting only the distinct ones).

The product of its (nonzero) digits is 87480, while the sum is 39.

The square root of 309905436 is about 17604.1312196882. The cubic root of 309905436 is about 676.7211210461.

The spelling of 309905436 in words is "three hundred nine million, nine hundred five thousand, four hundred thirty-six".