25557620 has 72 divisors (see below), whose sum is σ = 60328800. Its totient is φ = 9085120.

The previous prime is 25557599. The next prime is 25557629. The reversal of 25557620 is 2675552.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (25557629) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 142691 + ... + 142869.

It is an arithmetic number, because the mean of its divisors is an integer number (837900).

Almost surely, 2^25557620 is an apocalyptic number.

25557620 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 25557620, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (30164400).

25557620 is an abundant number, since it is smaller than the sum of its proper divisors (34771180).

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

25557620 is a wasteful number, since it uses less digits than its factorization.

25557620 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 269 (or 256 counting only the distinct ones).

The product of its (nonzero) digits is 21000, while the sum is 32.

The square root of 25557620 is about 5055.4544800641. The cubic root of 25557620 is about 294.5597954225.

It can be divided in two parts, 255 and 57620, that added together give a palindrome (57875).

The spelling of 25557620 in words is "twenty-five million, five hundred fifty-seven thousand, six hundred twenty".