722166391 has 2 divisors, whose sum is σ = 722166392. Its totient is φ = 722166390.

The previous prime is 722166377. The next prime is 722166427. The reversal of 722166391 is 193661227.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 722166391 - 2⁹ = 722165879 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 722166391.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (722166331) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 361083195 + 361083196.

It is an arithmetic number, because the mean of its divisors is an integer number (361083196).

Almost surely, 2^722166391 is an apocalyptic number.

722166391 is a deficient number, since it is larger than the sum of its proper divisors (1).

722166391 is an equidigital number, since it uses as much as digits as its factorization.

722166391 is an evil number, because the sum of its binary digits is even.

The product of its digits is 27216, while the sum is 37.

The square root of 722166391 is about 26873.1537226281. The cubic root of 722166391 is about 897.1789820850.

The spelling of 722166391 in words is "seven hundred twenty-two million, one hundred sixty-six thousand, three hundred ninety-one".