309147920 has 20 divisors (see below), whose sum is σ = 718769100. Its totient is φ = 123659136.

The previous prime is 309147901. The next prime is 309147953. The reversal of 309147920 is 29741903.

It can be written as a sum of positive squares in 2 ways, for example, as 169624576 + 139523344 = 13024^2 + 11812^2 .

It is a tau number, because it is divible by the number of its divisors (20).

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, 1932095 + ... + 1932254.

It is an arithmetic number, because the mean of its divisors is an integer number (35938455).

Almost surely, 2^309147920 is an apocalyptic number.

It is an amenable number.

309147920 is an abundant number, since it is smaller than the sum of its proper divisors (409621180).

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

309147920 is a wasteful number, since it uses less digits than its factorization.

309147920 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3864362 (or 3864356 counting only the distinct ones).

The product of its (nonzero) digits is 13608, while the sum is 35.

The square root of 309147920 is about 17582.6027652336. The cubic root of 309147920 is about 676.1692910742.

The spelling of 309147920 in words is "three hundred nine million, one hundred forty-seven thousand, nine hundred twenty".