21120975 has 18 divisors (see below), whose sum is σ = 37830416. Its totient is φ = 11264400.

The previous prime is 21120959. The next prime is 21121003. The reversal of 21120975 is 57902112.

It is not a de Polignac number, because 21120975 - 2⁴ = 21120959 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 17 ways as a sum of consecutive naturals, for example, 46711 + ... + 47160.

Almost surely, 2^21120975 is an apocalyptic number.

21120975 is a gapful number since it is divisible by the number (25) formed by its first and last digit.

21120975 is a deficient number, since it is larger than the sum of its proper divisors (16709441).

21120975 is a wasteful number, since it uses less digits than its factorization.

21120975 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 93887 (or 93879 counting only the distinct ones).

The product of its (nonzero) digits is 1260, while the sum is 27.

The square root of 21120975 is about 4595.7561945778. The cubic root of 21120975 is about 276.4211827099.

The spelling of 21120975 in words is "twenty-one million, one hundred twenty thousand, nine hundred seventy-five".