25661254656 has 176 divisors, whose sum is σ = 73246900320. Its totient is φ = 7958691840.

The previous prime is 25661254643. The next prime is 25661254687. The reversal of 25661254656 is 65645216652.

It is a Harshad number since it is a multiple of its sum of digits (48).

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, 4645176 + ... + 4650696.

It is an arithmetic number, because the mean of its divisors is an integer number (416175570).

Almost surely, 2^25661254656 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 25661254656, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (36623450160).

25661254656 is an abundant number, since it is smaller than the sum of its proper divisors (47585645664).

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

25661254656 is a wasteful number, since it uses less digits than its factorization.

25661254656 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5650 (or 5632 counting only the distinct ones).

The product of its digits is 2592000, while the sum is 48.

The spelling of 25661254656 in words is "twenty-five billion, six hundred sixty-one million, two hundred fifty-four thousand, six hundred fifty-six".