22720391 has 2 divisors, whose sum is σ = 22720392. Its totient is φ = 22720390.

The previous prime is 22720363. The next prime is 22720393. The reversal of 22720391 is 19302722.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 22720391 - 2¹⁴ = 22704007 is a prime.

It is a Sophie Germain prime.

Together with 22720393, it forms a pair of twin primes.

It is a Chen prime.

It is a self number, because there is not a number n which added to its sum of digits gives 22720391.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (22720393) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 11360195 + 11360196.

It is an arithmetic number, because the mean of its divisors is an integer number (11360196).

Almost surely, 2^22720391 is an apocalyptic number.

22720391 is a deficient number, since it is larger than the sum of its proper divisors (1).

22720391 is an equidigital number, since it uses as much as digits as its factorization.

22720391 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 1512, while the sum is 26.

The square root of 22720391 is about 4766.5911299376. The cubic root of 22720391 is about 283.2295747719.

The spelling of 22720391 in words is "twenty-two million, seven hundred twenty thousand, three hundred ninety-one".