25581428320 has 96 divisors (see below), whose sum is σ = 69150751488. Its totient is φ = 8760503808.

The previous prime is 25581428269. The next prime is 25581428347. The reversal of 25581428320 is 2382418552.

It is a Harshad number since it is a multiple of its sum of digits (40).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 976027 + ... + 1001893.

It is an arithmetic number, because the mean of its divisors is an integer number (720320328).

Almost surely, 2^25581428320 is an apocalyptic number.

25581428320 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 25581428320, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (34575375744).

25581428320 is an abundant number, since it is smaller than the sum of its proper divisors (43569323168).

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

25581428320 is a wasteful number, since it uses less digits than its factorization.

25581428320 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 26772 (or 26764 counting only the distinct ones).

The product of its (nonzero) digits is 153600, while the sum is 40.

The spelling of 25581428320 in words is "twenty-five billion, five hundred eighty-one million, four hundred twenty-eight thousand, three hundred twenty".