21903525 has 36 divisors (see below), whose sum is σ = 44839392. Its totient is φ = 10012320.

The previous prime is 21903509. The next prime is 21903527. The reversal of 21903525 is 52530912.

It is not a de Polignac number, because 21903525 - 2⁴ = 21903509 is a prime.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21903527) by changing a digit.

It is a polite number, since it can be written in 35 ways as a sum of consecutive naturals, for example, 5379 + ... + 8528.

Almost surely, 2^21903525 is an apocalyptic number.

21903525 is a gapful number since it is divisible by the number (25) formed by its first and last digit.

It is an amenable number.

21903525 is an abundant number, since it is smaller than the sum of its proper divisors (22935867).

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

21903525 is a wasteful number, since it uses less digits than its factorization.

21903525 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 13930 (or 13922 counting only the distinct ones).

The product of its (nonzero) digits is 2700, while the sum is 27.

The square root of 21903525 is about 4680.1201907643. The cubic root of 21903525 is about 279.7937469171.

The spelling of 21903525 in words is "twenty-one million, nine hundred three thousand, five hundred twenty-five".