21380875 has 8 divisors (see below), whose sum is σ = 26683488. Its totient is φ = 17104600.

The previous prime is 21380867. The next prime is 21380881. The reversal of 21380875 is 57808312.

It is not a de Polignac number, because 21380875 - 2³ = 21380867 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 21380875.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 85399 + ... + 85648.

It is an arithmetic number, because the mean of its divisors is an integer number (3335436).

Almost surely, 2^21380875 is an apocalyptic number.

21380875 is a gapful number since it is divisible by the number (25) formed by its first and last digit.

21380875 is a deficient number, since it is larger than the sum of its proper divisors (5302613).

21380875 is an equidigital number, since it uses as much as digits as its factorization.

21380875 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 171062 (or 171052 counting only the distinct ones).

The product of its (nonzero) digits is 13440, while the sum is 34.

The square root of 21380875 is about 4623.9458258072. The cubic root of 21380875 is about 277.5503790794.

The spelling of 21380875 in words is "twenty-one million, three hundred eighty thousand, eight hundred seventy-five".