9991000097977 has 2 divisors, whose sum is σ = 9991000097978. Its totient is φ = 9991000097976.

The previous prime is 9991000097951. The next prime is 9991000098041. The reversal of 9991000097977 is 7797900001999.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 6811807683136 + 3179192414841 = 2609944^2 + 1783029^2 .

It is a cyclic number.

It is not a de Polignac number, because 9991000097977 - 2³⁵ = 9956640359609 is a prime.

It is not a weakly prime, because it can be changed into another prime (9991001097977) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 4995500048988 + 4995500048989.

It is an arithmetic number, because the mean of its divisors is an integer number (4995500048989).

Almost surely, 2^{9991000097977} is an apocalyptic number.

It is an amenable number.

9991000097977 is a deficient number, since it is larger than the sum of its proper divisors (1).

9991000097977 is an equidigital number, since it uses as much as digits as its factorization.

9991000097977 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 20253807, while the sum is 67.

The spelling of 9991000097977 in words is "nine trillion, nine hundred ninety-one billion, ninety-seven thousand, nine hundred seventy-seven".