21456875 has 20 divisors (see below), whose sum is σ = 29259384. Its totient is φ = 15600000.

The previous prime is 21456859. The next prime is 21456881. The reversal of 21456875 is 57865412.

It is not a de Polignac number, because 21456875 - 2⁴ = 21456859 is a prime.

It is an unprimeable number.

It is a polite number, since it can be written in 19 ways as a sum of consecutive naturals, for example, 5315 + ... + 8435.

Almost surely, 2^21456875 is an apocalyptic number.

21456875 is a gapful number since it is divisible by the number (25) formed by its first and last digit.

21456875 is a deficient number, since it is larger than the sum of its proper divisors (7802509).

21456875 is an equidigital number, since it uses as much as digits as its factorization.

21456875 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3152 (or 3137 counting only the distinct ones).

The product of its digits is 67200, while the sum is 38.

The square root of 21456875 is about 4632.1566251585. The cubic root of 21456875 is about 277.8788484057.

The spelling of 21456875 in words is "twenty-one million, four hundred fifty-six thousand, eight hundred seventy-five".