1397887931 has 16 divisors (see below), whose sum is σ = 1606824960. Its totient is φ = 1202726880.

The previous prime is 1397887919. The next prime is 1397887943.

1397887931 is nontrivially palindromic in base 10.

It is an interprime number because it is at equal distance from previous prime (1397887919) and next prime (1397887943).

It is a cyclic number.

It is not a de Polignac number, because 1397887931 - 2¹⁰ = 1397886907 is a prime.

It is a super-2 number, since 2×1397887931² = 3908181335270921522, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (1397887961) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 255830 + ... + 261236.

It is an arithmetic number, because the mean of its divisors is an integer number (100426560).

Almost surely, 2^1397887931 is an apocalyptic number.

1397887931 is a gapful number since it is divisible by the number (11) formed by its first and last digit.

1397887931 is a deficient number, since it is larger than the sum of its proper divisors (208937029).

1397887931 is a wasteful number, since it uses less digits than its factorization.

1397887931 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 6674.

The product of its digits is 2286144, while the sum is 56.

The square root of 1397887931 is about 37388.3395057871. The cubic root of 1397887931 is about 1118.1260998443.

The spelling of 1397887931 in words is "one billion, three hundred ninety-seven million, eight hundred eighty-seven thousand, nine hundred thirty-one".