26564645631 has 4 divisors (see below), whose sum is σ = 35419527512. Its totient is φ = 17709763752.

The previous prime is 26564645609. The next prime is 26564645641. The reversal of 26564645631 is 13654646562.

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

It is not a de Polignac number, because 26564645631 - 2⁹ = 26564645119 is a prime.

It is a super-2 number, since 2×26564645631² (a number of 22 digits) contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (26564645641) 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, 4427440936 + ... + 4427440941.

It is an arithmetic number, because the mean of its divisors is an integer number (8854881878).

Almost surely, 2^26564645631 is an apocalyptic number.

26564645631 is a deficient number, since it is larger than the sum of its proper divisors (8854881881).

26564645631 is an equidigital number, since it uses as much as digits as its factorization.

26564645631 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 8854881880.

The product of its digits is 3110400, while the sum is 48.

The spelling of 26564645631 in words is "twenty-six billion, five hundred sixty-four million, six hundred forty-five thousand, six hundred thirty-one".