11566987951 has 4 divisors (see below), whose sum is σ = 11713405600. Its totient is φ = 11420570304.

The previous prime is 11566987931. The next prime is 11566987963. The reversal of 11566987951 is 15978966511.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 11566987951 - 2²⁵ = 11533433519 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (11566987931) 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 3 ways as a sum of consecutive naturals, for example, 73208706 + ... + 73208863.

It is an arithmetic number, because the mean of its divisors is an integer number (2928351400).

Almost surely, 2^11566987951 is an apocalyptic number.

11566987951 is a deficient number, since it is larger than the sum of its proper divisors (146417649).

11566987951 is an equidigital number, since it uses as much as digits as its factorization.

11566987951 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 146417648.

The product of its digits is 4082400, while the sum is 58.

The spelling of 11566987951 in words is "eleven billion, five hundred sixty-six million, nine hundred eighty-seven thousand, nine hundred fifty-one".