21722375 has 8 divisors (see below), whose sum is σ = 27109680. Its totient is φ = 17377800.

The previous prime is 21722359. The next prime is 21722381. The reversal of 21722375 is 57322712.

It is not a de Polignac number, because 21722375 - 2⁴ = 21722359 is a prime.

It is a congruent 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 7 ways as a sum of consecutive naturals, for example, 86765 + ... + 87014.

It is an arithmetic number, because the mean of its divisors is an integer number (3388710).

Almost surely, 2^21722375 is an apocalyptic number.

21722375 is a gapful number since it is divisible by the number (25) formed by its first and last digit.

21722375 is a deficient number, since it is larger than the sum of its proper divisors (5387305).

21722375 is an equidigital number, since it uses as much as digits as its factorization.

21722375 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 173794 (or 173784 counting only the distinct ones).

The product of its digits is 5880, while the sum is 29.

The square root of 21722375 is about 4660.7268746409. The cubic root of 21722375 is about 279.0202791835.

The spelling of 21722375 in words is "twenty-one million, seven hundred twenty-two thousand, three hundred seventy-five".