25231979520 has 440 divisors, whose sum is σ = 98654722848. Its totient is φ = 6115737600.

The previous prime is 25231979519. The next prime is 25231979543. The reversal of 25231979520 is 2597913252.

25231979520 is a `hidden beast` number, since 2 + 5 + 2 + 31 + 97 + 9 + 520 = 666.

It is a tau number, because it is divible by the number of its divisors (440).

It is a Harshad number since it is a multiple of its sum of digits (45).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 39 ways as a sum of consecutive naturals, for example, 4559155 + ... + 4564685.

Almost surely, 2^25231979520 is an apocalyptic number.

25231979520 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 25231979520, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (49327361424).

25231979520 is an abundant number, since it is smaller than the sum of its proper divisors (73422743328).

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

25231979520 is a wasteful number, since it uses less digits than its factorization.

25231979520 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5579 (or 5552 counting only the distinct ones).

The product of its (nonzero) digits is 340200, while the sum is 45.

The spelling of 25231979520 in words is "twenty-five billion, two hundred thirty-one million, nine hundred seventy-nine thousand, five hundred twenty".