22513721 has 2 divisors, whose sum is σ = 22513722. Its totient is φ = 22513720.

The previous prime is 22513693. The next prime is 22513741. The reversal of 22513721 is 12731522.

It is a happy number.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 17131321 + 5382400 = 4139^2 + 2320^2 .

It is a cyclic number.

It is not a de Polignac number, because 22513721 - 2¹⁰ = 22512697 is a prime.

It is not a weakly prime, because it can be changed into another prime (22513741) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 11256860 + 11256861.

It is an arithmetic number, because the mean of its divisors is an integer number (11256861).

Almost surely, 2^22513721 is an apocalyptic number.

It is an amenable number.

22513721 is a deficient number, since it is larger than the sum of its proper divisors (1).

22513721 is an equidigital number, since it uses as much as digits as its factorization.

22513721 is an evil number, because the sum of its binary digits is even.

The product of its digits is 840, while the sum is 23.

The square root of 22513721 is about 4744.8625902127. The cubic root of 22513721 is about 282.3681834713.

The spelling of 22513721 in words is "twenty-two million, five hundred thirteen thousand, seven hundred twenty-one".