9715991 has 2 divisors, whose sum is σ = 9715992. Its totient is φ = 9715990.

The previous prime is 9715969. The next prime is 9716017. The reversal of 9715991 is 1995179.

It is a happy number.

It is a weak prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-9715991 is a prime.

It is a super-2 number, since 2×9715991² = 188800962224162, which contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (9715931) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 4857995 + 4857996.

It is an arithmetic number, because the mean of its divisors is an integer number (4857996).

Almost surely, 2^9715991 is an apocalyptic number.

9715991 is a deficient number, since it is larger than the sum of its proper divisors (1).

9715991 is an equidigital number, since it uses as much as digits as its factorization.

9715991 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 25515, while the sum is 41.

The square root of 9715991 is about 3117.0484436402. The cubic root of 9715991 is about 213.3842535242.

The spelling of 9715991 in words is "nine million, seven hundred fifteen thousand, nine hundred ninety-one".