21901375 has 8 divisors (see below), whose sum is σ = 27333072. Its totient is φ = 17521000.

The previous prime is 21901291. The next prime is 21901381. The reversal of 21901375 is 57310912.

It is not a de Polignac number, because 21901375 - 2⁷ = 21901247 is a prime.

It is a Duffinian number.

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, 87481 + ... + 87730.

It is an arithmetic number, because the mean of its divisors is an integer number (3416634).

Almost surely, 2^21901375 is an apocalyptic number.

21901375 is a gapful number since it is divisible by the number (25) formed by its first and last digit.

21901375 is a deficient number, since it is larger than the sum of its proper divisors (5431697).

21901375 is an equidigital number, since it uses as much as digits as its factorization.

21901375 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 175226 (or 175216 counting only the distinct ones).

The product of its (nonzero) digits is 1890, while the sum is 28.

The square root of 21901375 is about 4679.8904901718. The cubic root of 21901375 is about 279.7845919791.

The spelling of 21901375 in words is "twenty-one million, nine hundred one thousand, three hundred seventy-five".