25821918864 has 135 divisors (see below), whose sum is σ = 84107925993. Its totient is φ = 7373834496.

The previous prime is 25821918841. The next prime is 25821918877. The reversal of 25821918864 is 46881912852.

The square root of 25821918864 is 160692.

It is a perfect power (a square), and thus also a powerful number.

It can be written as a sum of positive squares in only one way, i.e., 22482003600 + 3339915264 = 149940^2 + 57792^2 .

It is a self number, because there is not a number n which added to its sum of digits gives 25821918864.

It is an unprimeable number.

It is a polite number, since it can be written in 26 ways as a sum of consecutive naturals, for example, 13497172 + ... + 13499084.

Almost surely, 2^25821918864 is an apocalyptic number.

25821918864 is a gapful number since it is divisible by the number (24) formed by its first and last digit.

25821918864 is the 160692-nd square number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 25821918864

25821918864 is an abundant number, since it is smaller than the sum of its proper divisors (58286007129).

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

25821918864 is an equidigital number, since it uses as much as digits as its factorization.

25821918864 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3854 (or 1925 counting only the distinct ones).

The product of its digits is 2211840, while the sum is 54.

The spelling of 25821918864 in words is "twenty-five billion, eight hundred twenty-one million, nine hundred eighteen thousand, eight hundred sixty-four".