21270875 has 8 divisors (see below), whose sum is σ = 26546208. Its totient is φ = 17016600.

The previous prime is 21270871. The next prime is 21270877. The reversal of 21270875 is 57807212.

It is not a de Polignac number, because 21270875 - 2² = 21270871 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21270871) by changing a digit.

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 7 ways as a sum of consecutive naturals, for example, 84959 + ... + 85208.

It is an arithmetic number, because the mean of its divisors is an integer number (3318276).

Almost surely, 2^21270875 is an apocalyptic number.

21270875 is a gapful number since it is divisible by the number (25) formed by its first and last digit.

21270875 is a deficient number, since it is larger than the sum of its proper divisors (5275333).

21270875 is an equidigital number, since it uses as much as digits as its factorization.

21270875 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 170182 (or 170172 counting only the distinct ones).

The product of its (nonzero) digits is 7840, while the sum is 32.

The square root of 21270875 is about 4612.0358845091. The cubic root of 21270875 is about 277.0735814810.

The spelling of 21270875 in words is "twenty-one million, two hundred seventy thousand, eight hundred seventy-five".