309208712 has 12 divisors (see below), whose sum is σ = 579859605. Its totient is φ = 154579488.

The previous prime is 309208703. The next prime is 309208721. The reversal of 309208712 is 217802903.

It is a powerful number, because all its prime factors have an exponent greater than 1 and also an Achilles number because it is not a perfect power.

It is an interprime number because it is at equal distance from previous prime (309208703) and next prime (309208721).

It can be written as a sum of positive squares in 2 ways, for example, as 290838916 + 18369796 = 17054^2 + 4286^2 .

It is an ABA number since it can be written as A⋅B^A, here for A=2, B=12434.

It is a super-2 number, since 2×309208712² = 191220055153397888, which contains 22 as substring.

It is a Duffinian number.

It is an unprimeable number.

It is a polite number, since it can be written in 2 ways as a sum of consecutive naturals, for example, 46628 + ... + 52844.

Almost surely, 2^309208712 is an apocalyptic number.

It is an amenable number.

309208712 is a deficient number, since it is larger than the sum of its proper divisors (270650893).

309208712 is an frugal number, since it uses more digits than its factorization.

309208712 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 12440 (or 6219 counting only the distinct ones).

The product of its (nonzero) digits is 6048, while the sum is 32.

The square root of 309208712 is about 17584.3314345471. The cubic root of 309208712 is about 676.2136096531.

Multiplying 309208712 by its sum of digits (32), we get a square (9894678784 = 99472²).

The spelling of 309208712 in words is "three hundred nine million, two hundred eight thousand, seven hundred twelve".