21895923 has 16 divisors (see below), whose sum is σ = 35121920. Its totient is φ = 11853216.

The previous prime is 21895921. The next prime is 21895933. The reversal of 21895923 is 32959812.

It is not a de Polignac number, because 21895923 - 2¹ = 21895921 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21895921) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 27040 + ... + 27837.

It is an arithmetic number, because the mean of its divisors is an integer number (2195120).

Almost surely, 2^21895923 is an apocalyptic number.

21895923 is a deficient number, since it is larger than the sum of its proper divisors (13225997).

21895923 is a wasteful number, since it uses less digits than its factorization.

21895923 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 54906.

The product of its digits is 38880, while the sum is 39.

The square root of 21895923 is about 4679.3079616542. The cubic root of 21895923 is about 279.7613740732.

It can be divided in two parts, 218 and 95923, that added together give a triangular number (96141 = T₄₃₈).

The spelling of 21895923 in words is "twenty-one million, eight hundred ninety-five thousand, nine hundred twenty-three".