25663638672 has 640 divisors, whose sum is σ = 91676672000. Its totient is φ = 6858432000.

The previous prime is 25663638667. The next prime is 25663638683. The reversal of 25663638672 is 27683636652.

25663638672 is a `hidden beast` number, since 2 + 566 + 3 + 6 + 3 + 8 + 6 + 72 = 666.

It is a Harshad number since it is a multiple of its sum of digits (54).

It is an unprimeable number.

It is a polite number, since it can be written in 127 ways as a sum of consecutive naturals, for example, 169957797 + ... + 169957947.

It is an arithmetic number, because the mean of its divisors is an integer number (143244800).

Almost surely, 2^25663638672 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 25663638672, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (45838336000).

25663638672 is an abundant number, since it is smaller than the sum of its proper divisors (66013033328).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

25663638672 is a wasteful number, since it uses less digits than its factorization.

25663638672 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 257 (or 231 counting only the distinct ones).

The product of its digits is 13063680, while the sum is 54.

The spelling of 25663638672 in words is "twenty-five billion, six hundred sixty-three million, six hundred thirty-eight thousand, six hundred seventy-two".