21716875 has 10 divisors (see below), whose sum is σ = 27138188. Its totient is φ = 17373000.

The previous prime is 21716869. The next prime is 21716881. The reversal of 21716875 is 57861712.

It is an interprime number because it is at equal distance from previous prime (21716869) and next prime (21716881).

It is a de Polignac number, because none of the positive numbers 2^k-21716875 is a prime.

It is a Duffinian number.

It is an unprimeable number.

It is a polite number, since it can be written in 9 ways as a sum of consecutive naturals, for example, 16749 + ... + 17998.

Almost surely, 2^21716875 is an apocalyptic number.

21716875 is a gapful number since it is divisible by the number (25) formed by its first and last digit.

21716875 is a deficient number, since it is larger than the sum of its proper divisors (5421313).

21716875 is an frugal number, since it uses more digits than its factorization.

21716875 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 34767 (or 34752 counting only the distinct ones).

The product of its digits is 23520, while the sum is 37.

The square root of 21716875 is about 4660.1368005671. The cubic root of 21716875 is about 278.9967283353.

The spelling of 21716875 in words is "twenty-one million, seven hundred sixteen thousand, eight hundred seventy-five".