91117812 has 48 divisors (see below), whose sum is σ = 226074240. Its totient is φ = 28499328.

The previous prime is 91117811. The next prime is 91117813. The reversal of 91117812 is 21871119.

It is an interprime number because it is at equal distance from previous prime (91117811) and next prime (91117813).

It is a self number, because there is not a number n which added to its sum of digits gives 91117812.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (91117811) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 11514 + ... + 17742.

It is an arithmetic number, because the mean of its divisors is an integer number (4709880).

Almost surely, 2^91117812 is an apocalyptic number.

91117812 is a gapful number since it is divisible by the number (92) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 91117812, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (113037120).

91117812 is an abundant number, since it is smaller than the sum of its proper divisors (134956428).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

91117812 is a wasteful number, since it uses less digits than its factorization.

91117812 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 6312 (or 6310 counting only the distinct ones).

The product of its digits is 1008, while the sum is 30.

The square root of 91117812 is about 9545.5650435163. The cubic root of 91117812 is about 449.9881675901.

The spelling of 91117812 in words is "ninety-one million, one hundred seventeen thousand, eight hundred twelve".