25517638980 has 84 divisors (see below), whose sum is σ = 80343854892. Its totient is φ = 6804699840.

The previous prime is 25517638969. The next prime is 25517638981. The reversal of 25517638980 is 8983671552.

25517638980 is a `hidden beast` number, since 2 + 5 + 517 + 6 + 38 + 98 + 0 = 666.

It can be written as a sum of positive squares in 2 ways, for example, as 8496783684 + 17020855296 = 92178^2 + 130464^2 .

It is a super-3 number, since 3×25517638980³ (a number of 32 digits) contains 333 as substring. Note that it is a super-d number also for d = 2.

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

It is not an unprimeable number, because it can be changed into a prime (25517638981) by changing a digit.

It is a polite number, since it can be written in 27 ways as a sum of consecutive naturals, for example, 860511 + ... + 889670.

It is an arithmetic number, because the mean of its divisors is an integer number (956474463).

Almost surely, 2^25517638980 is an apocalyptic number.

25517638980 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

25517638980 is an abundant number, since it is smaller than the sum of its proper divisors (54826215912).

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

25517638980 is a wasteful number, since it uses less digits than its factorization.

25517638980 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1750208 (or 1750191 counting only the distinct ones).

The product of its (nonzero) digits is 3628800, while the sum is 54.

The spelling of 25517638980 in words is "twenty-five billion, five hundred seventeen million, six hundred thirty-eight thousand, nine hundred eighty".