21525885 has 32 divisors (see below), whose sum is σ = 38465280. Its totient is φ = 11421504.

The previous prime is 21525883. The next prime is 21525899. The reversal of 21525885 is 58852512.

21525885 is a `hidden beast` number, since 21 + 52 + 588 + 5 = 666.

It is not a de Polignac number, because 21525885 - 2¹ = 21525883 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21525883) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 42544 + ... + 43046.

It is an arithmetic number, because the mean of its divisors is an integer number (1202040).

Almost surely, 2^21525885 is an apocalyptic number.

It is an amenable number.

21525885 is a deficient number, since it is larger than the sum of its proper divisors (16939395).

21525885 is a wasteful number, since it uses less digits than its factorization.

21525885 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 834 (or 828 counting only the distinct ones).

The product of its digits is 32000, while the sum is 36.

The square root of 21525885 is about 4639.5996594534. The cubic root of 21525885 is about 278.1764359694.

The spelling of 21525885 in words is "twenty-one million, five hundred twenty-five thousand, eight hundred eighty-five".