91812 has 24 divisors (see below), whose sum is σ = 245056. Its totient is φ = 26208.

The previous prime is 91811. The next prime is 91813. The reversal of 91812 is 21819.

It is an interprime number because it is at equal distance from previous prime (91811) and next prime (91813).

It is a Harshad number since it is a multiple of its sum of digits (21).

It is an inconsummate number, since it does not exist a number n which divided by its sum of digits gives 91812.

It is not an unprimeable number, because it can be changed into a prime (91811) 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, 463 + ... + 630.

2⁹¹⁸¹² is an apocalyptic number.

It is an amenable number.

91812 is an abundant number, since it is smaller than the sum of its proper divisors (153244).

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

It is a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (122528).

91812 is a wasteful number, since it uses less digits than its factorization.

91812 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1107 (or 1105 counting only the distinct ones).

The product of its digits is 144, while the sum is 21.

The square root of 91812 is about 303.0049504546. The cubic root of 91812 is about 45.1128034144.

It can be divided in two parts, 91 and 812, that added together give a triangular number (903 = T₄₂).

The spelling of 91812 in words is "ninety-one thousand, eight hundred twelve".