1391864931 has 64 divisors (see below), whose sum is σ = 2225932800. Its totient is φ = 856977408.

The previous prime is 1391864921. The next prime is 1391865011. The reversal of 1391864931 is 1394681931.

1391864931 is digitally balanced in base 4, because in such base it contains all the possibile digits an equal number of times.

It is not a de Polignac number, because 1391864931 - 2¹¹ = 1391862883 is a prime.

It is a super-2 number, since 2×1391864931² = 3874575972295269522, which contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (1391864921) 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, 4129995 + ... + 4130331.

It is an arithmetic number, because the mean of its divisors is an integer number (34780200).

Almost surely, 2^1391864931 is an apocalyptic number.

1391864931 is a deficient number, since it is larger than the sum of its proper divisors (834067869).

1391864931 is a wasteful number, since it uses less digits than its factorization.

1391864931 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 545 (or 539 counting only the distinct ones).

The product of its digits is 139968, while the sum is 45.

The square root of 1391864931 is about 37307.7060538436. The cubic root of 1391864931 is about 1116.5179192179.

The spelling of 1391864931 in words is "one billion, three hundred ninety-one million, eight hundred sixty-four thousand, nine hundred thirty-one".