21133975 has 12 divisors (see below), whose sum is σ = 27748224. Its totient is φ = 15912320.

The previous prime is 21133967. The next prime is 21133979. The reversal of 21133975 is 57933112.

It is not a de Polignac number, because 21133975 - 2³ = 21133967 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21133979) 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 11 ways as a sum of consecutive naturals, for example, 24439 + ... + 25288.

It is an arithmetic number, because the mean of its divisors is an integer number (2312352).

Almost surely, 2^21133975 is an apocalyptic number.

21133975 is a gapful number since it is divisible by the number (25) formed by its first and last digit.

21133975 is a deficient number, since it is larger than the sum of its proper divisors (6614249).

21133975 is a wasteful number, since it uses less digits than its factorization.

21133975 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 49754 (or 49749 counting only the distinct ones).

The product of its digits is 5670, while the sum is 31.

The square root of 21133975 is about 4597.1703253197. The cubic root of 21133975 is about 276.4778836650.

The spelling of 21133975 in words is "twenty-one million, one hundred thirty-three thousand, nine hundred seventy-five".