21723896 has 8 divisors (see below), whose sum is σ = 40732320. Its totient is φ = 10861944.

The previous prime is 21723883. The next prime is 21723907. The reversal of 21723896 is 69832712.

It is a tau number, because it is divible by the number of its divisors (8).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 1357736 + ... + 1357751.

It is an arithmetic number, because the mean of its divisors is an integer number (5091540).

Almost surely, 2^21723896 is an apocalyptic number.

It is an amenable number.

21723896 is a deficient number, since it is larger than the sum of its proper divisors (19008424).

21723896 is a wasteful number, since it uses less digits than its factorization.

21723896 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2715493 (or 2715489 counting only the distinct ones).

The product of its digits is 36288, while the sum is 38.

The square root of 21723896 is about 4660.8900437577. The cubic root of 21723896 is about 279.0267913619.

The spelling of 21723896 in words is "twenty-one million, seven hundred twenty-three thousand, eight hundred ninety-six".