21873525 has 12 divisors (see below), whose sum is σ = 36164352. Its totient is φ = 11665840.

The previous prime is 21873521. The next prime is 21873539. The reversal of 21873525 is 52537812.

It is not a de Polignac number, because 21873525 - 2² = 21873521 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21873521) 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, 145749 + ... + 145898.

It is an arithmetic number, because the mean of its divisors is an integer number (3013696).

Almost surely, 2^21873525 is an apocalyptic number.

21873525 is a gapful number since it is divisible by the number (25) formed by its first and last digit.

It is an amenable number.

21873525 is a deficient number, since it is larger than the sum of its proper divisors (14290827).

21873525 is a wasteful number, since it uses less digits than its factorization.

21873525 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 291660 (or 291655 counting only the distinct ones).

The product of its digits is 16800, while the sum is 33.

The square root of 21873525 is about 4676.9140466765. The cubic root of 21873525 is about 279.6659494126.

The spelling of 21873525 in words is "twenty-one million, eight hundred seventy-three thousand, five hundred twenty-five".