397988657 has 8 divisors (see below), whose sum is σ = 436353600. Its totient is φ = 359987760.

The previous prime is 397988651. The next prime is 397988677. The reversal of 397988657 is 756889793.

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 397988657 - 2¹⁴ = 397972273 is a prime.

It is a super-2 number, since 2×397988657² = 316789942201327298, which contains 22 as substring.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 397988657.

It is not an unprimeable number, because it can be changed into a prime (397988651) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 88718 + ... + 93095.

It is an arithmetic number, because the mean of its divisors is an integer number (54544200).

Almost surely, 2^397988657 is an apocalyptic number.

It is an amenable number.

397988657 is a deficient number, since it is larger than the sum of its proper divisors (38364943).

397988657 is a wasteful number, since it uses less digits than its factorization.

397988657 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 182023.

The product of its digits is 22861440, while the sum is 62.

The square root of 397988657 is about 19949.6530546273. The cubic root of 397988657 is about 735.5692487995.

The spelling of 397988657 in words is "three hundred ninety-seven million, nine hundred eighty-eight thousand, six hundred fifty-seven".