21105938 has 16 divisors (see below), whose sum is σ = 36723264. Its totient is φ = 8910000.

The previous prime is 21105913. The next prime is 21105967. The reversal of 21105938 is 83950112.

It is a self number, because there is not a number n which added to its sum of digits gives 21105938.

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, 10313 + ... + 12188.

It is an arithmetic number, because the mean of its divisors is an integer number (2295204).

Almost surely, 2^21105938 is an apocalyptic number.

21105938 is a deficient number, since it is larger than the sum of its proper divisors (15617326).

21105938 is a wasteful number, since it uses less digits than its factorization.

21105938 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 22577.

The product of its (nonzero) digits is 2160, while the sum is 29.

The square root of 21105938 is about 4594.1199374853. The cubic root of 21105938 is about 276.3555681233.

The spelling of 21105938 in words is "twenty-one million, one hundred five thousand, nine hundred thirty-eight".