9999957715961 has 2 divisors, whose sum is σ = 9999957715962. Its totient is φ = 9999957715960.

The previous prime is 9999957715907. The next prime is 9999957716011. The reversal of 9999957715961 is 1695177599999.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 9814786716736 + 185170999225 = 3132856^2 + 430315^2 .

It is a cyclic number.

It is not a de Polignac number, because 9999957715961 - 2³⁸ = 9725079809017 is a prime.

It is not a weakly prime, because it can be changed into another prime (9999957715901) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 4999978857980 + 4999978857981.

It is an arithmetic number, because the mean of its divisors is an integer number (4999978857981).

Almost surely, 2^{9999957715961} is an apocalyptic number.

It is an amenable number.

9999957715961 is a deficient number, since it is larger than the sum of its proper divisors (1).

9999957715961 is an equidigital number, since it uses as much as digits as its factorization.

9999957715961 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 3906091350, while the sum is 86.

The spelling of 9999957715961 in words is "nine trillion, nine hundred ninety-nine billion, nine hundred fifty-seven million, seven hundred fifteen thousand, nine hundred sixty-one".