21900375 has 96 divisors (see below), whose sum is σ = 47244288. Its totient is φ = 9914400.

The previous prime is 21900371. The next prime is 21900377. The reversal of 21900375 is 57300912.

It is not a de Polignac number, because 21900375 - 2² = 21900371 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (27).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21900371) by changing a digit.

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 95 ways as a sum of consecutive naturals, for example, 212574 + ... + 212676.

It is an arithmetic number, because the mean of its divisors is an integer number (492128).

Almost surely, 2^21900375 is an apocalyptic number.

21900375 is a gapful number since it is divisible by the number (25) formed by its first and last digit.

21900375 is an abundant number, since it is smaller than the sum of its proper divisors (25343913).

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

21900375 is an equidigital number, since it uses as much as digits as its factorization.

21900375 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 140 (or 118 counting only the distinct ones).

The product of its (nonzero) digits is 1890, while the sum is 27.

The square root of 21900375 is about 4679.7836488453. The cubic root of 21900375 is about 279.7803336642.

The spelling of 21900375 in words is "twenty-one million, nine hundred thousand, three hundred seventy-five".