21027875 has 32 divisors (see below), whose sum is σ = 29405376. Its totient is φ = 14880000.

The previous prime is 21027863. The next prime is 21027887. The reversal of 21027875 is 57872012.

It is an interprime number because it is at equal distance from previous prime (21027863) and next prime (21027887).

It is not a de Polignac number, because 21027875 - 2¹⁰ = 21026851 is a prime.

It is an unprimeable number.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 56189 + ... + 56561.

It is an arithmetic number, because the mean of its divisors is an integer number (918918).

Almost surely, 2^21027875 is an apocalyptic number.

21027875 is a gapful number since it is divisible by the number (25) formed by its first and last digit.

21027875 is a deficient number, since it is larger than the sum of its proper divisors (8377501).

21027875 is a wasteful number, since it uses less digits than its factorization.

21027875 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 440 (or 430 counting only the distinct ones).

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

The square root of 21027875 is about 4585.6160981923. The cubic root of 21027875 is about 276.0144351128.

Adding to 21027875 its reverse (57872012), we get a palindrome (78899887).

The spelling of 21027875 in words is "twenty-one million, twenty-seven thousand, eight hundred seventy-five".