397872731 has 4 divisors (see below), whose sum is σ = 400313832. Its totient is φ = 395431632.

The previous prime is 397872707. The next prime is 397872737. The reversal of 397872731 is 137278793.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 137278793 = 1913 ⋅71761.

It is a cyclic number.

It is not a de Polignac number, because 397872731 - 2⁶ = 397872667 is a prime.

It is a super-2 number, since 2×397872731² = 316605420146796722, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (397872737) 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, 1220306 + ... + 1220631.

It is an arithmetic number, because the mean of its divisors is an integer number (100078458).

Almost surely, 2^397872731 is an apocalyptic number.

397872731 is a deficient number, since it is larger than the sum of its proper divisors (2441101).

397872731 is a wasteful number, since it uses less digits than its factorization.

397872731 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2441100.

The product of its digits is 444528, while the sum is 47.

The square root of 397872731 is about 19946.7473789588. The cubic root of 397872731 is about 735.4978230776.

The spelling of 397872731 in words is "three hundred ninety-seven million, eight hundred seventy-two thousand, seven hundred thirty-one".