397931311 has 4 divisors (see below), whose sum is σ = 398416824. Its totient is φ = 397445800.

The previous prime is 397931309. The next prime is 397931327. The reversal of 397931311 is 113139793.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 113139793 = 13 ⋅8703061.

It is a cyclic number.

It is not a de Polignac number, because 397931311 - 2¹ = 397931309 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (397931351) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 241525 + ... + 243166.

It is an arithmetic number, because the mean of its divisors is an integer number (99604206).

Almost surely, 2^397931311 is an apocalyptic number.

397931311 is a deficient number, since it is larger than the sum of its proper divisors (485513).

397931311 is an equidigital number, since it uses as much as digits as its factorization.

397931311 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 485512.

The product of its digits is 15309, while the sum is 37.

The square root of 397931311 is about 19948.2157347468. The cubic root of 397931311 is about 735.5339178258.

The spelling of 397931311 in words is "three hundred ninety-seven million, nine hundred thirty-one thousand, three hundred eleven".