717139987 has 2 divisors, whose sum is σ = 717139988. Its totient is φ = 717139986.

The previous prime is 717139961. The next prime is 717139993. The reversal of 717139987 is 789931717.

717139987 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a strong prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-717139987 is a prime.

It is not a weakly prime, because it can be changed into another prime (717139937) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 358569993 + 358569994.

It is an arithmetic number, because the mean of its divisors is an integer number (358569994).

Almost surely, 2^717139987 is an apocalyptic number.

717139987 is a deficient number, since it is larger than the sum of its proper divisors (1).

717139987 is an equidigital number, since it uses as much as digits as its factorization.

717139987 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 666792, while the sum is 52.

The square root of 717139987 is about 26779.4695055746. The cubic root of 717139987 is about 895.0926267231.

The spelling of 717139987 in words is "seven hundred seventeen million, one hundred thirty-nine thousand, nine hundred eighty-seven".