25623521 has 24 divisors (see below), whose sum is σ = 32848416. Its totient is φ = 19763520.

The previous prime is 25623509. The next prime is 25623527. The reversal of 25623521 is 12532652.

25623521 = 699² + 700² + ... + 747².

It is not a de Polignac number, because 25623521 - 2¹⁸ = 25361377 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (25623527) 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, 73670 + ... + 74016.

It is an arithmetic number, because the mean of its divisors is an integer number (1368684).

Almost surely, 2^25623521 is an apocalyptic number.

It is an amenable number.

25623521 is a deficient number, since it is larger than the sum of its proper divisors (7224895).

25623521 is a wasteful number, since it uses less digits than its factorization.

25623521 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 509 (or 502 counting only the distinct ones).

The product of its digits is 3600, while the sum is 26.

The square root of 25623521 is about 5061.9680955138. The cubic root of 25623521 is about 294.8127548705.

The spelling of 25623521 in words is "twenty-five million, six hundred twenty-three thousand, five hundred twenty-one".