21590525 has 12 divisors (see below), whose sum is σ = 29206464. Its totient is φ = 15702000.

The previous prime is 21590521. The next prime is 21590533. The reversal of 21590525 is 52509512.

It is not a de Polignac number, because 21590525 - 2² = 21590521 is a prime.

It is a hoax number, since the sum of its digits (29) coincides with the sum of the digits of its distinct prime factors.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21590521) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 38981 + ... + 39530.

It is an arithmetic number, because the mean of its divisors is an integer number (2433872).

Almost surely, 2^21590525 is an apocalyptic number.

21590525 is a gapful number since it is divisible by the number (25) formed by its first and last digit.

It is an amenable number.

21590525 is a deficient number, since it is larger than the sum of its proper divisors (7615939).

21590525 is a wasteful number, since it uses less digits than its factorization.

21590525 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 78532 (or 78527 counting only the distinct ones).

The product of its (nonzero) digits is 4500, while the sum is 29.

The square root of 21590525 is about 4646.5605559381. The cubic root of 21590525 is about 278.4546027146.

The spelling of 21590525 in words is "twenty-one million, five hundred ninety thousand, five hundred twenty-five".