309315057921 has 27 divisors (see below), whose sum is σ = 452081951139. Its totient is φ = 203795187552.

The previous prime is 309315057907. The next prime is 309315057937. The reversal of 309315057921 is 129750513903.

The square root of 309315057921 is 556161.

It is a perfect power (a square), and thus also a powerful number.

309315057921 is a `hidden beast` number, since 3 + 0 + 9 + 3 + 1 + 50 + 579 + 21 = 666.

It can be written as a sum of positive squares in only one way, i.e., 59395051521 + 249920006400 = 243711^2 + 499920^2 .

It is not a de Polignac number, because 309315057921 - 2¹⁵ = 309315025153 is a prime.

It is not an unprimeable number, because it can be changed into a prime (309315057901) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 26 ways as a sum of consecutive naturals, for example, 148493946 + ... + 148496028.

Almost surely, 2^309315057921 is an apocalyptic number.

309315057921 is the 556161-st square number.

309315057921 is the 278081-st centered octagonal number.

It is an amenable number.

309315057921 is a deficient number, since it is larger than the sum of its proper divisors (142766893218).

309315057921 is an frugal number, since it uses more digits than its factorization.

309315057921 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4350 (or 2175 counting only the distinct ones).

The product of its (nonzero) digits is 255150, while the sum is 45.

The spelling of 309315057921 in words is "three hundred nine billion, three hundred fifteen million, fifty-seven thousand, nine hundred twenty-one".