22220115721 has 2 divisors, whose sum is σ = 22220115722. Its totient is φ = 22220115720.

The previous prime is 22220115703. The next prime is 22220115733. The reversal of 22220115721 is 12751102222.

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., 22123290121 + 96825600 = 148739^2 + 9840^2 .

It is a cyclic number.

It is not a de Polignac number, because 22220115721 - 2⁹ = 22220115209 is a prime.

It is not a weakly prime, because it can be changed into another prime (22220115791) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 11110057860 + 11110057861.

It is an arithmetic number, because the mean of its divisors is an integer number (11110057861).

Almost surely, 2^22220115721 is an apocalyptic number.

It is an amenable number.

22220115721 is a deficient number, since it is larger than the sum of its proper divisors (1).

22220115721 is an equidigital number, since it uses as much as digits as its factorization.

22220115721 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 1120, while the sum is 25.

Adding to 22220115721 its reverse (12751102222), we get a palindrome (34971217943).

The spelling of 22220115721 in words is "twenty-two billion, two hundred twenty million, one hundred fifteen thousand, seven hundred twenty-one".