21622723 has 2 divisors, whose sum is σ = 21622724. Its totient is φ = 21622722.

The previous prime is 21622693. The next prime is 21622739. The reversal of 21622723 is 32722612.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 21622723 - 2¹⁷ = 21491651 is a prime.

It is not a weakly prime, because it can be changed into another prime (21622123) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10811361 + 10811362.

It is an arithmetic number, because the mean of its divisors is an integer number (10811362).

Almost surely, 2^21622723 is an apocalyptic number.

21622723 is a deficient number, since it is larger than the sum of its proper divisors (1).

21622723 is an equidigital number, since it uses as much as digits as its factorization.

21622723 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 2016, while the sum is 25.

The square root of 21622723 is about 4650.0239784328. The cubic root of 21622723 is about 278.5929539611.

The spelling of 21622723 in words is "twenty-one million, six hundred twenty-two thousand, seven hundred twenty-three".