21310875 has 48 divisors (see below), whose sum is σ = 40478880. Its totient is φ = 10756800.

The previous prime is 21310871. The next prime is 21310889. The reversal of 21310875 is 57801312.

It is not a de Polignac number, because 21310875 - 2² = 21310871 is a prime.

It is not an unprimeable number, because it can be changed into a prime (21310871) 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 47 ways as a sum of consecutive naturals, for example, 20877 + ... + 21873.

It is an arithmetic number, because the mean of its divisors is an integer number (843310).

Almost surely, 2^21310875 is an apocalyptic number.

21310875 is a gapful number since it is divisible by the number (25) formed by its first and last digit.

21310875 is a deficient number, since it is larger than the sum of its proper divisors (19168005).

21310875 is a wasteful number, since it uses less digits than its factorization.

21310875 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1037 (or 1024 counting only the distinct ones).

The product of its (nonzero) digits is 1680, while the sum is 27.

The square root of 21310875 is about 4616.3703274326. The cubic root of 21310875 is about 277.2471522020.

The spelling of 21310875 in words is "twenty-one million, three hundred ten thousand, eight hundred seventy-five".