1287996931 has 16 divisors (see below), whose sum is σ = 1428824320. Its totient is φ = 1153504800.

The previous prime is 1287996929. The next prime is 1287996953. The reversal of 1287996931 is 1396997821.

It is a cyclic number.

It is not a de Polignac number, because 1287996931 - 2¹ = 1287996929 is a prime.

It is a super-2 number, since 2×1287996931² = 3317872188530837522, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (1287996911) 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, 76780 + ... + 92038.

It is an arithmetic number, because the mean of its divisors is an integer number (89301520).

Almost surely, 2^1287996931 is an apocalyptic number.

1287996931 is a deficient number, since it is larger than the sum of its proper divisors (140827389).

1287996931 is a wasteful number, since it uses less digits than its factorization.

1287996931 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 15466.

The product of its digits is 1469664, while the sum is 55.

The square root of 1287996931 is about 35888.6741326564. The cubic root of 1287996931 is about 1088.0235009139.

The spelling of 1287996931 in words is "one billion, two hundred eighty-seven million, nine hundred ninety-six thousand, nine hundred thirty-one".