21430875 has 16 divisors (see below), whose sum is σ = 35661600. Its totient is φ = 11429600.

The previous prime is 21430861. The next prime is 21430909. The reversal of 21430875 is 57803412.

It is not a de Polignac number, because 21430875 - 2⁴ = 21430859 is a prime.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 28200 + ... + 28949.

It is an arithmetic number, because the mean of its divisors is an integer number (2228850).

Almost surely, 2^21430875 is an apocalyptic number.

21430875 is a gapful number since it is divisible by the number (25) formed by its first and last digit.

21430875 is a deficient number, since it is larger than the sum of its proper divisors (14230725).

21430875 is an equidigital number, since it uses as much as digits as its factorization.

21430875 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 57167 (or 57157 counting only the distinct ones).

The product of its (nonzero) digits is 6720, while the sum is 30.

The square root of 21430875 is about 4629.3493063281. The cubic root of 21430875 is about 277.7665647326.

The spelling of 21430875 in words is "twenty-one million, four hundred thirty thousand, eight hundred seventy-five".