21711875 has 10 divisors (see below), whose sum is σ = 27131940. Its totient is φ = 17369000.

The previous prime is 21711857. The next prime is 21711883. The reversal of 21711875 is 57811712.

It is not a de Polignac number, because 21711875 - 2⁸ = 21711619 is a prime.

It is an unprimeable number.

It is a polite number, since it can be written in 9 ways as a sum of consecutive naturals, for example, 16745 + ... + 17994.

It is an arithmetic number, because the mean of its divisors is an integer number (2713194).

Almost surely, 2^21711875 is an apocalyptic number.

21711875 is a gapful number since it is divisible by the number (25) formed by its first and last digit.

21711875 is a deficient number, since it is larger than the sum of its proper divisors (5420065).

21711875 is an frugal number, since it uses more digits than its factorization.

21711875 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 34759 (or 34744 counting only the distinct ones).

The product of its digits is 3920, while the sum is 32.

The square root of 21711875 is about 4659.6003047472. The cubic root of 21711875 is about 278.9753150225.

The spelling of 21711875 in words is "twenty-one million, seven hundred eleven thousand, eight hundred seventy-five".