397308921 has 16 divisors (see below), whose sum is σ = 570106368. Its totient is φ = 245203200.

The previous prime is 397308911. The next prime is 397308941. The reversal of 397308921 is 129803793.

It is not a de Polignac number, because 397308921 - 2¹⁴ = 397292537 is a prime.

It is not an unprimeable number, because it can be changed into a prime (397308911) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 60745 + ... + 66966.

It is an arithmetic number, because the mean of its divisors is an integer number (35631648).

Almost surely, 2^397308921 is an apocalyptic number.

It is an amenable number.

397308921 is a deficient number, since it is larger than the sum of its proper divisors (172797447).

397308921 is a wasteful number, since it uses less digits than its factorization.

397308921 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 127792.

The product of its (nonzero) digits is 81648, while the sum is 42.

The square root of 397308921 is about 19932.6094879722. The cubic root of 397308921 is about 735.1502437088.

The spelling of 397308921 in words is "three hundred ninety-seven million, three hundred eight thousand, nine hundred twenty-one".