21058624 has 28 divisors (see below), whose sum is σ = 42922444. Its totient is φ = 10243584.

The previous prime is 21058621. The next prime is 21058633. The reversal of 21058624 is 42685012.

It can be written as a sum of positive squares in 2 ways, for example, as 11022400 + 10036224 = 3320^2 + 3168^2 .

It is a junction number, because it is equal to n+sod(n) for n = 21058592 and 21058601.

It is not an unprimeable number, because it can be changed into a prime (21058621) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (7) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 2079 + ... + 6814.

Almost surely, 2^21058624 is an apocalyptic number.

It is an amenable number.

21058624 is an abundant number, since it is smaller than the sum of its proper divisors (21863820).

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

21058624 is an equidigital number, since it uses as much as digits as its factorization.

21058624 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 8942 (or 8932 counting only the distinct ones).

The product of its (nonzero) digits is 3840, while the sum is 28.

The square root of 21058624 is about 4588.9676398946. The cubic root of 21058624 is about 276.1489079543.

The spelling of 21058624 in words is "twenty-one million, fifty-eight thousand, six hundred twenty-four".