21104975 has 6 divisors (see below), whose sum is σ = 26170200. Its totient is φ = 16883960.

The previous prime is 21104947. The next prime is 21104981. The reversal of 21104975 is 57940112.

It is not a de Polignac number, because 21104975 - 2¹⁶ = 21039439 is a prime.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 422075 + ... + 422124.

It is an arithmetic number, because the mean of its divisors is an integer number (4361700).

Almost surely, 2^21104975 is an apocalyptic number.

21104975 is a gapful number since it is divisible by the number (25) formed by its first and last digit.

21104975 is a deficient number, since it is larger than the sum of its proper divisors (5065225).

21104975 is an equidigital number, since it uses as much as digits as its factorization.

21104975 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 844209 (or 844204 counting only the distinct ones).

The product of its (nonzero) digits is 2520, while the sum is 29.

The square root of 21104975 is about 4594.0151284035. The cubic root of 21104975 is about 276.3513649703.

The spelling of 21104975 in words is "twenty-one million, one hundred four thousand, nine hundred seventy-five".