99991211032031 has 4 divisors (see below), whose sum is σ = 109081321125864. Its totient is φ = 90901100938200.

The previous prime is 99991211031989. The next prime is 99991211032049. The reversal of 99991211032031 is 13023011219999.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 99991211032031 - 2⁶ = 99991211031967 is a prime.

It is a super-6 number, since 6×99991211032031⁶ (a number of 85 digits) contains 666666 as substring. Note that it is a super-d number also for d = 2.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (99991211032231) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 4545055046900 + ... + 4545055046921.

It is an arithmetic number, because the mean of its divisors is an integer number (27270330281466).

Almost surely, 2^{99991211032031} is an apocalyptic number.

99991211032031 is a deficient number, since it is larger than the sum of its proper divisors (9090110093833).

99991211032031 is a wasteful number, since it uses less digits than its factorization.

99991211032031 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 9090110093832.

The product of its (nonzero) digits is 236196, while the sum is 50.

The spelling of 99991211032031 in words is "ninety-nine trillion, nine hundred ninety-one billion, two hundred eleven million, thirty-two thousand, thirty-one".