722776721 has 2 divisors, whose sum is σ = 722776722. Its totient is φ = 722776720.

The previous prime is 722776693. The next prime is 722776793. The reversal of 722776721 is 127677227.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 689587600 + 33189121 = 26260^2 + 5761^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-722776721 is a prime.

It is not a weakly prime, because it can be changed into another prime (722776421) 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, 361388360 + 361388361.

It is an arithmetic number, because the mean of its divisors is an integer number (361388361).

Almost surely, 2^722776721 is an apocalyptic number.

It is an amenable number.

722776721 is a deficient number, since it is larger than the sum of its proper divisors (1).

722776721 is an equidigital number, since it uses as much as digits as its factorization.

722776721 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 115248, while the sum is 41.

The square root of 722776721 is about 26884.5070812169. The cubic root of 722776721 is about 897.4316574926.

The spelling of 722776721 in words is "seven hundred twenty-two million, seven hundred seventy-six thousand, seven hundred twenty-one".