718771561 has 2 divisors, whose sum is σ = 718771562. Its totient is φ = 718771560.

The previous prime is 718771523. The next prime is 718771567. The reversal of 718771561 is 165177817.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 674960400 + 43811161 = 25980^2 + 6619^2 .

It is a cyclic number.

It is not a de Polignac number, because 718771561 - 2⁹ = 718771049 is a prime.

It is not a weakly prime, because it can be changed into another prime (718771567) 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, 359385780 + 359385781.

It is an arithmetic number, because the mean of its divisors is an integer number (359385781).

Almost surely, 2^718771561 is an apocalyptic number.

It is an amenable number.

718771561 is a deficient number, since it is larger than the sum of its proper divisors (1).

718771561 is an equidigital number, since it uses as much as digits as its factorization.

718771561 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 82320, while the sum is 43.

The square root of 718771561 is about 26809.9153486168. The cubic root of 718771561 is about 895.7709246610.

The spelling of 718771561 in words is "seven hundred eighteen million, seven hundred seventy-one thousand, five hundred sixty-one".