309872385 has 56 divisors (see below), whose sum is σ = 562204224. Its totient is φ = 163879200.

The previous prime is 309872359. The next prime is 309872389. The reversal of 309872385 is 583278903.

It is not a de Polignac number, because 309872385 - 2¹² = 309868289 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (45).

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

It is a self number, because there is not a number n which added to its sum of digits gives 309872385.

It is not an unprimeable number, because it can be changed into a prime (309872389) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 55 ways as a sum of consecutive naturals, for example, 550114 + ... + 550676.

Almost surely, 2^309872385 is an apocalyptic number.

It is an amenable number.

309872385 is a deficient number, since it is larger than the sum of its proper divisors (252331839).

309872385 is an equidigital number, since it uses as much as digits as its factorization.

309872385 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 737 (or 722 counting only the distinct ones).

The product of its (nonzero) digits is 362880, while the sum is 45.

The square root of 309872385 is about 17603.1924661409. The cubic root of 309872385 is about 676.6970630568.

The spelling of 309872385 in words is "three hundred nine million, eight hundred seventy-two thousand, three hundred eighty-five".