718620989 has 2 divisors, whose sum is σ = 718620990. Its totient is φ = 718620988.

The previous prime is 718620967. The next prime is 718621019. The reversal of 718620989 is 989026817.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 587335225 + 131285764 = 24235^2 + 11458^2 .

It is a cyclic number.

It is not a de Polignac number, because 718620989 - 2⁸ = 718620733 is a prime.

It is a super-2 number, since 2×718620989² = 1032832251662676242, which contains 22 as substring.

It is a Sophie Germain prime.

It is a Curzon number.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (718620589) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 359310494 + 359310495.

It is an arithmetic number, because the mean of its divisors is an integer number (359310495).

Almost surely, 2^718620989 is an apocalyptic number.

It is an amenable number.

718620989 is a deficient number, since it is larger than the sum of its proper divisors (1).

718620989 is an equidigital number, since it uses as much as digits as its factorization.

718620989 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 435456, while the sum is 50.

The square root of 718620989 is about 26807.1070613746. The cubic root of 718620989 is about 895.7083700440.

The spelling of 718620989 in words is "seven hundred eighteen million, six hundred twenty thousand, nine hundred eighty-nine".