397086921 has 64 divisors (see below), whose sum is σ = 736819200. Its totient is φ = 205329600.

The previous prime is 397086917. The next prime is 397086929. The reversal of 397086921 is 129680793.

It is not a de Polignac number, because 397086921 - 2² = 397086917 is a prime.

It is not an unprimeable number, because it can be changed into a prime (397086929) by changing a digit.

It is a polite number, since it can be written in 63 ways as a sum of consecutive naturals, for example, 808486 + ... + 808976.

It is an arithmetic number, because the mean of its divisors is an integer number (11512800).

Almost surely, 2^397086921 is an apocalyptic number.

It is an amenable number.

397086921 is a deficient number, since it is larger than the sum of its proper divisors (339732279).

397086921 is a wasteful number, since it uses less digits than its factorization.

397086921 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 907 (or 901 counting only the distinct ones).

The product of its (nonzero) digits is 163296, while the sum is 45.

The square root of 397086921 is about 19927.0399457621. The cubic root of 397086921 is about 735.0132942202.

The spelling of 397086921 in words is "three hundred ninety-seven million, eighty-six thousand, nine hundred twenty-one".