11857997531 has 12 divisors (see below), whose sum is σ = 12105733800. Its totient is φ = 11611924800.

The previous prime is 11857997497. The next prime is 11857997537. The reversal of 11857997531 is 13579975811.

It is a happy number.

It is not a de Polignac number, because 11857997531 - 2¹⁴ = 11857981147 is a prime.

It is a super-2 number, since 2×11857997531² (a number of 21 digits) contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (11857997537) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 16915481 + ... + 16916181.

It is an arithmetic number, because the mean of its divisors is an integer number (1008811150).

Almost surely, 2^11857997531 is an apocalyptic number.

11857997531 is a deficient number, since it is larger than the sum of its proper divisors (247736269).

11857997531 is an frugal number, since it uses more digits than its factorization.

11857997531 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1870 (or 1169 counting only the distinct ones).

The product of its digits is 2381400, while the sum is 56.

The spelling of 11857997531 in words is "eleven billion, eight hundred fifty-seven million, nine hundred ninety-seven thousand, five hundred thirty-one".