11564212661 has 4 divisors (see below), whose sum is σ = 11574511392. Its totient is φ = 11553913932.

The previous prime is 11564212657. The next prime is 11564212691. The reversal of 11564212661 is 16621246511.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 11564212661 - 2² = 11564212657 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 (11564212601) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 5147681 + ... + 5149926.

It is an arithmetic number, because the mean of its divisors is an integer number (2893627848).

Almost surely, 2^11564212661 is an apocalyptic number.

It is an amenable number.

11564212661 is a deficient number, since it is larger than the sum of its proper divisors (10298731).

11564212661 is a wasteful number, since it uses less digits than its factorization.

11564212661 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 10298730.

The product of its digits is 17280, while the sum is 35.

The spelling of 11564212661 in words is "eleven billion, five hundred sixty-four million, two hundred twelve thousand, six hundred sixty-one".