21377875 has 8 divisors (see below), whose sum is σ = 26679744. Its totient is φ = 17102200.

The previous prime is 21377861. The next prime is 21377929. The reversal of 21377875 is 57877312.

It is not a de Polignac number, because 21377875 - 2¹⁹ = 20853587 is a prime.

It is a Duffinian number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 85387 + ... + 85636.

It is an arithmetic number, because the mean of its divisors is an integer number (3334968).

Almost surely, 2^21377875 is an apocalyptic number.

21377875 is a gapful number since it is divisible by the number (25) formed by its first and last digit.

21377875 is a deficient number, since it is larger than the sum of its proper divisors (5301869).

21377875 is an equidigital number, since it uses as much as digits as its factorization.

21377875 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 171038 (or 171028 counting only the distinct ones).

The product of its digits is 82320, while the sum is 40.

The square root of 21377875 is about 4623.6214161629. The cubic root of 21377875 is about 277.5373972271.

The spelling of 21377875 in words is "twenty-one million, three hundred seventy-seven thousand, eight hundred seventy-five".