99999999991807 has 2 divisors, whose sum is σ = 99999999991808. Its totient is φ = 99999999991806.

The previous prime is 99999999991741. The next prime is 99999999991831. The reversal of 99999999991807 is 70819999999999.

It is a strong prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-99999999991807 is a prime.

It is a super-2 number, since 2×99999999991807² (a number of 29 digits) contains 22 as substring.

It is a self number, because there is not a number n which added to its sum of digits gives 99999999991807.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (99999999991867) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (29) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 49999999995903 + 49999999995904.

It is an arithmetic number, because the mean of its divisors is an integer number (49999999995904).

Almost surely, 2^{99999999991807} is an apocalyptic number.

99999999991807 is a deficient number, since it is larger than the sum of its proper divisors (1).

99999999991807 is an equidigital number, since it uses as much as digits as its factorization.

99999999991807 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 195259926456, while the sum is 106.

The spelling of 99999999991807 in words is "ninety-nine trillion, nine hundred ninety-nine billion, nine hundred ninety-nine million, nine hundred ninety-one thousand, eight hundred seven".