21994875 has 128 divisors (see below), whose sum is σ = 49920000. Its totient is φ = 9525600.

The previous prime is 21994867. The next prime is 21994897. The reversal of 21994875 is 57849912.

It is not a de Polignac number, because 21994875 - 2³ = 21994867 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (45).

It is a taxicab number since it can be written as a sum of two cubes in more than one way. Here 21994875 = 35³ + 280³ = 99³ + 276³.

Its product of digits (181440) is a multiple of the sum of its prime factors (64).

It is a self number, because there is not a number n which added to its sum of digits gives 21994875.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 127 ways as a sum of consecutive naturals, for example, 1157616 + ... + 1157634.

It is an arithmetic number, because the mean of its divisors is an integer number (390000).

Almost surely, 2^21994875 is an apocalyptic number.

21994875 is a gapful number since it is divisible by the number (25) formed by its first and last digit.

21994875 is an abundant number, since it is smaller than the sum of its proper divisors (27925125).

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

21994875 is an equidigital number, since it uses as much as digits as its factorization.

21994875 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 64 (or 34 counting only the distinct ones).

The product of its digits is 181440, while the sum is 45.

The square root of 21994875 is about 4689.8694011667. The cubic root of 21994875 is about 280.1821731158.

The spelling of 21994875 in words is "twenty-one million, nine hundred ninety-four thousand, eight hundred seventy-five".