722226721 has 2 divisors, whose sum is σ = 722226722. Its totient is φ = 722226720.

The previous prime is 722226719. The next prime is 722226761. The reversal of 722226721 is 127622227.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 689325025 + 32901696 = 26255^2 + 5736^2 .

It is a cyclic number.

It is not a de Polignac number, because 722226721 - 2¹ = 722226719 is a prime.

It is a super-2 number, since 2×722226721² = 1043222873052823682, which contains 22 as substring.

Together with 722226719, it forms a pair of twin primes.

It is not a weakly prime, because it can be changed into another prime (722226761) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 361113360 + 361113361.

It is an arithmetic number, because the mean of its divisors is an integer number (361113361).

Almost surely, 2^722226721 is an apocalyptic number.

It is an amenable number.

722226721 is a deficient number, since it is larger than the sum of its proper divisors (1).

722226721 is an equidigital number, since it uses as much as digits as its factorization.

722226721 is an evil number, because the sum of its binary digits is even.

The product of its digits is 9408, while the sum is 31.

The square root of 722226721 is about 26874.2761949043. The cubic root of 722226721 is about 897.2039649243.

Adding to 722226721 its reverse (127622227), we get a palindrome (849848948).

The spelling of 722226721 in words is "seven hundred twenty-two million, two hundred twenty-six thousand, seven hundred twenty-one".