309872 has 20 divisors (see below), whose sum is σ = 609336. Its totient is φ = 152640.

The previous prime is 309857. The next prime is 309877. The reversal of 309872 is 278903.

It is an alternating number because its digits alternate between odd and even.

It is a congruent number.

It is an inconsummate number, since it does not exist a number n which divided by its sum of digits gives 309872.

It is not an unprimeable number, because it can be changed into a prime (309877) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1622 + ... + 1802.

2³⁰⁹⁸⁷² is an apocalyptic number.

It is an amenable number.

309872 is a deficient number, since it is larger than the sum of its proper divisors (299464).

309872 is a wasteful number, since it uses less digits than its factorization.

309872 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 296 (or 290 counting only the distinct ones).

The product of its (nonzero) digits is 3024, while the sum is 29.

The square root of 309872 is about 556.6614770217. The cubic root of 309872 is about 67.6696782803.

The spelling of 309872 in words is "three hundred nine thousand, eight hundred seventy-two".