715991 has 2 divisors, whose sum is σ = 715992. Its totient is φ = 715990.

The previous prime is 715973. The next prime is 715999. The reversal of 715991 is 199517.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 715991 - 2⁶ = 715927 is a prime.

It is a super-2 number, since 2×715991² = 1025286224162, which contains 22 as substring.

It is a Chen prime.

It is a congruent number.

It is an inconsummate number, since it does not exist a number n which divided by its sum of digits gives 715991.

It is not a weakly prime, because it can be changed into another prime (715999) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 357995 + 357996.

It is an arithmetic number, because the mean of its divisors is an integer number (357996).

2⁷¹⁵⁹⁹¹ is an apocalyptic number.

715991 is a deficient number, since it is larger than the sum of its proper divisors (1).

715991 is an equidigital number, since it uses as much as digits as its factorization.

715991 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 2835, while the sum is 32.

The square root of 715991 is about 846.1625139416. The cubic root of 715991 is about 89.4614338172.

The spelling of 715991 in words is "seven hundred fifteen thousand, nine hundred ninety-one".