396861631 has 4 divisors (see below), whose sum is σ = 397081152. Its totient is φ = 396642112.

The previous prime is 396861613. The next prime is 396861637. The reversal of 396861631 is 136168693.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 396861631 - 2⁵ = 396861599 is a prime.

It is a super-2 number, since 2×396861631² = 314998308319960322, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (396861637) 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, 107026 + ... + 110671.

It is an arithmetic number, because the mean of its divisors is an integer number (99270288).

Almost surely, 2^396861631 is an apocalyptic number.

396861631 is a deficient number, since it is larger than the sum of its proper divisors (219521).

396861631 is a wasteful number, since it uses less digits than its factorization.

396861631 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 219520.

The product of its digits is 139968, while the sum is 43.

The square root of 396861631 is about 19921.3862720444. The cubic root of 396861631 is about 734.8742629715.

The spelling of 396861631 in words is "three hundred ninety-six million, eight hundred sixty-one thousand, six hundred thirty-one".