25815520 has 48 divisors (see below), whose sum is σ = 64583568. Its totient is φ = 9717760.

The previous prime is 25815511. The next prime is 25815521. The reversal of 25815520 is 2551852.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (25815521) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 2026 + ... + 7465.

It is an arithmetic number, because the mean of its divisors is an integer number (1345491).

Almost surely, 2^25815520 is an apocalyptic number.

25815520 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

25815520 is an abundant number, since it is smaller than the sum of its proper divisors (38768048).

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

25815520 is a wasteful number, since it uses less digits than its factorization.

25815520 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 9523 (or 9515 counting only the distinct ones).

The product of its (nonzero) digits is 4000, while the sum is 28.

The square root of 25815520 is about 5080.8975585028. The cubic root of 25815520 is about 295.5472748061.

It can be divided in two parts, 25815 and 520, that added together give a triangular number (26335 = T₂₂₉).

The spelling of 25815520 in words is "twenty-five million, eight hundred fifteen thousand, five hundred twenty".