99043978717 has 2 divisors, whose sum is σ = 99043978718. Its totient is φ = 99043978716.

The previous prime is 99043978697. The next prime is 99043978723. The reversal of 99043978717 is 71787934099.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 80435199321 + 18608779396 = 283611^2 + 136414^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-99043978717 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (99043978757) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 49521989358 + 49521989359.

It is an arithmetic number, because the mean of its divisors is an integer number (49521989359).

Almost surely, 2^99043978717 is an apocalyptic number.

It is an amenable number.

99043978717 is a deficient number, since it is larger than the sum of its proper divisors (1).

99043978717 is an equidigital number, since it uses as much as digits as its factorization.

99043978717 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 24004512, while the sum is 64.

It can be divided in two parts, 990439 and 78717, that added together give a square (1069156 = 1034²).

The spelling of 99043978717 in words is "ninety-nine billion, forty-three million, nine hundred seventy-eight thousand, seven hundred seventeen".