21975875 has 24 divisors (see below), whose sum is σ = 29004768. Its totient is φ = 16621200.

The previous prime is 21975851. The next prime is 21975911. The reversal of 21975875 is 57857912.

It is not a de Polignac number, because 21975875 - 2¹⁰ = 21974851 is a prime.

It is a Duffinian number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 44882 + ... + 45368.

It is an arithmetic number, because the mean of its divisors is an integer number (1208532).

Almost surely, 2^21975875 is an apocalyptic number.

21975875 is a gapful number since it is divisible by the number (25) formed by its first and last digit.

21975875 is a deficient number, since it is larger than the sum of its proper divisors (7028893).

21975875 is an equidigital number, since it uses as much as digits as its factorization.

21975875 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 540 (or 511 counting only the distinct ones).

The product of its digits is 176400, while the sum is 44.

The square root of 21975875 is about 4687.8433207606. The cubic root of 21975875 is about 280.1014725754.

The spelling of 21975875 in words is "twenty-one million, nine hundred seventy-five thousand, eight hundred seventy-five".