22720909 has 2 divisors, whose sum is σ = 22720910. Its totient is φ = 22720908.

The previous prime is 22720889. The next prime is 22720921. The reversal of 22720909 is 90902722.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 21883684 + 837225 = 4678^2 + 915^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-22720909 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (22720939) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 11360454 + 11360455.

It is an arithmetic number, because the mean of its divisors is an integer number (11360455).

Almost surely, 2^22720909 is an apocalyptic number.

It is an amenable number.

22720909 is a deficient number, since it is larger than the sum of its proper divisors (1).

22720909 is an equidigital number, since it uses as much as digits as its factorization.

22720909 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 4536, while the sum is 31.

The square root of 22720909 is about 4766.6454661533. The cubic root of 22720909 is about 283.2317271968.

The spelling of 22720909 in words is "twenty-two million, seven hundred twenty thousand, nine hundred nine".