718391281 has 2 divisors, whose sum is σ = 718391282. Its totient is φ = 718391280.

The previous prime is 718391221. The next prime is 718391339. The reversal of 718391281 is 182193817.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 598291600 + 120099681 = 24460^2 + 10959^2 .

It is a cyclic number.

It is not a de Polignac number, because 718391281 - 2¹³ = 718383089 is a prime.

It is a super-2 number, since 2×718391281² = 1032172065233641922, which contains 22 as substring.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (718391221) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 359195640 + 359195641.

It is an arithmetic number, because the mean of its divisors is an integer number (359195641).

Almost surely, 2^718391281 is an apocalyptic number.

It is an amenable number.

718391281 is a deficient number, since it is larger than the sum of its proper divisors (1).

718391281 is an equidigital number, since it uses as much as digits as its factorization.

718391281 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 24192, while the sum is 40.

The square root of 718391281 is about 26802.8222581130. The cubic root of 718391281 is about 895.6129218136.

The spelling of 718391281 in words is "seven hundred eighteen million, three hundred ninety-one thousand, two hundred eighty-one".