22721287 has 2 divisors, whose sum is σ = 22721288. Its totient is φ = 22721286.

The previous prime is 22721267. The next prime is 22721317. The reversal of 22721287 is 78212722.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 22721287 - 2²³ = 14332679 is a prime.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (22721227) 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, 11360643 + 11360644.

It is an arithmetic number, because the mean of its divisors is an integer number (11360644).

Almost surely, 2^22721287 is an apocalyptic number.

22721287 is a deficient number, since it is larger than the sum of its proper divisors (1).

22721287 is an equidigital number, since it uses as much as digits as its factorization.

22721287 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 6272, while the sum is 31.

The square root of 22721287 is about 4766.6851165144. The cubic root of 22721287 is about 283.2332978645.

The spelling of 22721287 in words is "twenty-two million, seven hundred twenty-one thousand, two hundred eighty-seven".