25718921536 has 56 divisors (see below), whose sum is σ = 63629292096. Its totient is φ = 10020357120.

The previous prime is 25718921533. The next prime is 25718921549. The reversal of 25718921536 is 63512981752.

It is a tau number, because it is divible by the number of its divisors (56).

It is a super-2 number, since 2×25718921536² (a number of 22 digits) contains 22 as substring.

It is a self number, because there is not a number n which added to its sum of digits gives 25718921536.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (25718921533) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 2604541 + ... + 2614396.

Almost surely, 2^25718921536 is an apocalyptic number.

It is an amenable number.

25718921536 is an abundant number, since it is smaller than the sum of its proper divisors (37910370560).

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

25718921536 is a wasteful number, since it uses less digits than its factorization.

25718921536 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5218967 (or 5218957 counting only the distinct ones).

The product of its digits is 907200, while the sum is 49.

The spelling of 25718921536 in words is "twenty-five billion, seven hundred eighteen million, nine hundred twenty-one thousand, five hundred thirty-six".