91000001031 has 8 divisors (see below), whose sum is σ = 121432064880. Its totient is φ = 60617302272.

The previous prime is 91000001017. The next prime is 91000001039. The reversal of 91000001031 is 13010000019.

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 91000001031 - 2¹⁵ = 90999968263 is a prime.

It is a super-2 number, since 2×91000001031² (a number of 23 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 91000001031.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (91000001039) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 12336970 + ... + 12344343.

It is an arithmetic number, because the mean of its divisors is an integer number (15179008110).

Almost surely, 2^91000001031 is an apocalyptic number.

91000001031 is a deficient number, since it is larger than the sum of its proper divisors (30432063849).

91000001031 is a wasteful number, since it uses less digits than its factorization.

91000001031 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 24682545.

The product of its (nonzero) digits is 27, while the sum is 15.

The spelling of 91000001031 in words is "ninety-one billion, one thousand, thirty-one".