91032991031 has 4 divisors (see below), whose sum is σ = 91107793392. Its totient is φ = 90958188672.

The previous prime is 91032991001. The next prime is 91032991057. The reversal of 91032991031 is 13019923019.

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 91032991031 - 2¹⁰ = 91032990007 is a prime.

It is a super-2 number, since 2×91032991031² (a number of 23 digits) contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (91032991001) 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, 37399355 + ... + 37401788.

It is an arithmetic number, because the mean of its divisors is an integer number (22776948348).

Almost surely, 2^91032991031 is an apocalyptic number.

91032991031 is a deficient number, since it is larger than the sum of its proper divisors (74802361).

91032991031 is a wasteful number, since it uses less digits than its factorization.

91032991031 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 74802360.

The product of its (nonzero) digits is 13122, while the sum is 38.

The spelling of 91032991031 in words is "ninety-one billion, thirty-two million, nine hundred ninety-one thousand, thirty-one".