25557045640 has 96 divisors (see below), whose sum is σ = 66976787520. Its totient is φ = 8751265152.

The previous prime is 25557045623. The next prime is 25557045691. The reversal of 25557045640 is 4654075552.

It is an unprimeable number.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 1613037 + ... + 1628803.

It is an arithmetic number, because the mean of its divisors is an integer number (697674870).

Almost surely, 2^25557045640 is an apocalyptic number.

25557045640 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 25557045640, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (33488393760).

25557045640 is an abundant number, since it is smaller than the sum of its proper divisors (41419741880).

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

25557045640 is a wasteful number, since it uses less digits than its factorization.

25557045640 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 16619 (or 16608 counting only the distinct ones).

The product of its (nonzero) digits is 840000, while the sum is 43.

The spelling of 25557045640 in words is "twenty-five billion, five hundred fifty-seven million, forty-five thousand, six hundred forty".