25564505643 has 12 divisors (see below), whose sum is σ = 38870008840. Its totient is φ = 16146003456.

The previous prime is 25564505627. The next prime is 25564505683. The reversal of 25564505643 is 34650546552.

25564505643 is a `hidden beast` number, since 2 + 556 + 4 + 5 + 0 + 56 + 43 = 666.

It is not a de Polignac number, because 25564505643 - 2⁴ = 25564505627 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (25564505683) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 74749846 + ... + 74750187.

Almost surely, 2^25564505643 is an apocalyptic number.

25564505643 is a deficient number, since it is larger than the sum of its proper divisors (13305503197).

25564505643 is a wasteful number, since it uses less digits than its factorization.

25564505643 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 149500058 (or 149500055 counting only the distinct ones).

The product of its (nonzero) digits is 2160000, while the sum is 45.

The spelling of 25564505643 in words is "twenty-five billion, five hundred sixty-four million, five hundred five thousand, six hundred forty-three".