21058824 has 32 divisors (see below), whose sum is σ = 53244000. Its totient is φ = 6940032.

The previous prime is 21058819. The next prime is 21058853. The reversal of 21058824 is 42885012.

It is a junction number, because it is equal to n+sod(n) for n = 21058791 and 21058800.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 2794 + ... + 7065.

It is an arithmetic number, because the mean of its divisors is an integer number (1663875).

Almost surely, 2^21058824 is an apocalyptic number.

21058824 is a gapful number since it is divisible by the number (24) formed by its first and last digit.

It is an amenable number.

21058824 is an abundant number, since it is smaller than the sum of its proper divisors (32185176).

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

21058824 is a wasteful number, since it uses less digits than its factorization.

21058824 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 9957 (or 9953 counting only the distinct ones).

The product of its (nonzero) digits is 5120, while the sum is 30.

The square root of 21058824 is about 4588.9894312365. The cubic root of 21058824 is about 276.1497821742.

The spelling of 21058824 in words is "twenty-one million, fifty-eight thousand, eight hundred twenty-four".