21722323 has 4 divisors (see below), whose sum is σ = 24825520. Its totient is φ = 18619128.

The previous prime is 21722321. The next prime is 21722341. The reversal of 21722323 is 32322712.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 21722323 - 2¹ = 21722321 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 21722294 and 21722303.

It is not an unprimeable number, because it can be changed into a prime (21722321) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1551588 + ... + 1551601.

It is an arithmetic number, because the mean of its divisors is an integer number (6206380).

Almost surely, 2^21722323 is an apocalyptic number.

21722323 is a deficient number, since it is larger than the sum of its proper divisors (3103197).

21722323 is an equidigital number, since it uses as much as digits as its factorization.

21722323 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3103196.

The product of its digits is 1008, while the sum is 22.

The square root of 21722323 is about 4660.7212961086. The cubic root of 21722323 is about 279.0200565396.

The spelling of 21722323 in words is "twenty-one million, seven hundred twenty-two thousand, three hundred twenty-three".