21867725 has 18 divisors (see below), whose sum is σ = 29809290. Its totient is φ = 15901600.

The previous prime is 21867709. The next prime is 21867739. The reversal of 21867725 is 52776812.

It can be written as a sum of positive squares in 3 ways, for example, as 7382089 + 14485636 = 2717^2 + 3806^2 .

It is not a de Polignac number, because 21867725 - 2⁴ = 21867709 is a prime.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 17 ways as a sum of consecutive naturals, for example, 590 + ... + 6639.

Almost surely, 2^21867725 is an apocalyptic number.

21867725 is a gapful number since it is divisible by the number (25) formed by its first and last digit.

It is an amenable number.

21867725 is a deficient number, since it is larger than the sum of its proper divisors (7941565).

21867725 is a wasteful number, since it uses less digits than its factorization.

21867725 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 7261 (or 7245 counting only the distinct ones).

The product of its digits is 47040, while the sum is 38.

The square root of 21867725 is about 4676.2939385800. The cubic root of 21867725 is about 279.6412284178.

The spelling of 21867725 in words is "twenty-one million, eight hundred sixty-seven thousand, seven hundred twenty-five".