25506520 has 64 divisors (see below), whose sum is σ = 62375040. Its totient is φ = 9331200.

The previous prime is 25506497. The next prime is 25506557. The reversal of 25506520 is 2560552.

25506520 = 1297² + 1298² + ... + 1311².

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 93985 + ... + 94255.

It is an arithmetic number, because the mean of its divisors is an integer number (974610).

Almost surely, 2^25506520 is an apocalyptic number.

25506520 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 25506520, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (31187520).

25506520 is an abundant number, since it is smaller than the sum of its proper divisors (36868520).

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

25506520 is a wasteful number, since it uses less digits than its factorization.

25506520 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 476 (or 472 counting only the distinct ones).

The product of its (nonzero) digits is 3000, while the sum is 25.

The square root of 25506520 is about 5050.3980041181. The cubic root of 25506520 is about 294.3633497913.

The spelling of 25506520 in words is "twenty-five million, five hundred six thousand, five hundred twenty".