11566987931 has 2 divisors, whose sum is σ = 11566987932. Its totient is φ = 11566987930.

The previous prime is 11566987909. The next prime is 11566987963. The reversal of 11566987931 is 13978966511.

It is a weak prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-11566987931 is a prime.

It is a super-2 number, since 2×11566987931² (a number of 21 digits) contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (11566987331) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 5783493965 + 5783493966.

It is an arithmetic number, because the mean of its divisors is an integer number (5783493966).

Almost surely, 2^11566987931 is an apocalyptic number.

11566987931 is a deficient number, since it is larger than the sum of its proper divisors (1).

11566987931 is an equidigital number, since it uses as much as digits as its factorization.

11566987931 is an evil number, because the sum of its binary digits is even.

The product of its digits is 2449440, while the sum is 56.

The spelling of 11566987931 in words is "eleven billion, five hundred sixty-six million, nine hundred eighty-seven thousand, nine hundred thirty-one".