21872895 has 32 divisors (see below), whose sum is σ = 40193280. Its totient is φ = 10045440.

The previous prime is 21872891. The next prime is 21872923. The reversal of 21872895 is 59827812.

It is not a de Polignac number, because 21872895 - 2² = 21872891 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21872891) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 354 + ... + 6623.

It is an arithmetic number, because the mean of its divisors is an integer number (1256040).

Almost surely, 2^21872895 is an apocalyptic number.

21872895 is a deficient number, since it is larger than the sum of its proper divisors (18320385).

21872895 is a wasteful number, since it uses less digits than its factorization.

21872895 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 7015.

The product of its digits is 80640, while the sum is 42.

The square root of 21872895 is about 4676.8466940878. The cubic root of 21872895 is about 279.6632644127.

The spelling of 21872895 in words is "twenty-one million, eight hundred seventy-two thousand, eight hundred ninety-five".