21719875 has 16 divisors (see below), whose sum is σ = 27690624. Its totient is φ = 17001600.

The previous prime is 21719861. The next prime is 21719881. The reversal of 21719875 is 57891712.

It is not a de Polignac number, because 21719875 - 2¹¹ = 21717827 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 15 ways as a sum of consecutive naturals, for example, 4027 + ... + 7723.

It is an arithmetic number, because the mean of its divisors is an integer number (1730664).

Almost surely, 2^21719875 is an apocalyptic number.

21719875 is a gapful number since it is divisible by the number (25) formed by its first and last digit.

21719875 is a deficient number, since it is larger than the sum of its proper divisors (5970749).

21719875 is an equidigital number, since it uses as much as digits as its factorization.

21719875 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3759 (or 3749 counting only the distinct ones).

The product of its digits is 35280, while the sum is 40.

The square root of 21719875 is about 4660.4586684145. The cubic root of 21719875 is about 279.0095747454.

The spelling of 21719875 in words is "twenty-one million, seven hundred nineteen thousand, eight hundred seventy-five".