21867723 has 12 divisors (see below), whose sum is σ = 31648968. Its totient is φ = 14549760.

The previous prime is 21867709. The next prime is 21867739. The reversal of 21867723 is 32776812.

It is not a de Polignac number, because 21867723 - 2⁵ = 21867691 is a prime.

It is not an unprimeable number, because it can be changed into a prime (21867743) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 3088 + ... + 7298.

It is an arithmetic number, because the mean of its divisors is an integer number (2637414).

Almost surely, 2^21867723 is an apocalyptic number.

21867723 is a deficient number, since it is larger than the sum of its proper divisors (9781245).

21867723 is a wasteful number, since it uses less digits than its factorization.

21867723 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4794 (or 4791 counting only the distinct ones).

The product of its digits is 28224, while the sum is 36.

The square root of 21867723 is about 4676.2937247354. The cubic root of 21867723 is about 279.6412198925.

The spelling of 21867723 in words is "twenty-one million, eight hundred sixty-seven thousand, seven hundred twenty-three".