99999999991831 has 2 divisors, whose sum is σ = 99999999991832. Its totient is φ = 99999999991830.

The previous prime is 99999999991807. The next prime is 99999999991867. The reversal of 99999999991831 is 13819999999999.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 99999999991831 - 2¹¹ = 99999999989783 is a prime.

It is a super-2 number, since 2×99999999991831² (a number of 29 digits) contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (99999999991531) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 49999999995915 + 49999999995916.

It is an arithmetic number, because the mean of its divisors is an integer number (49999999995916).

Almost surely, 2^{99999999991831} is an apocalyptic number.

99999999991831 is a deficient number, since it is larger than the sum of its proper divisors (1).

99999999991831 is an equidigital number, since it uses as much as digits as its factorization.

99999999991831 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 83682825624, while the sum is 103.

The spelling of 99999999991831 in words is "ninety-nine trillion, nine hundred ninety-nine billion, nine hundred ninety-nine million, nine hundred ninety-one thousand, eight hundred thirty-one".