91872 has 72 divisors (see below), whose sum is σ = 294840. Its totient is φ = 26880.

The previous prime is 91867. The next prime is 91873. The reversal of 91872 is 27819.

It is a tau number, because it is divible by the number of its divisors (72).

It is an Ulam number.

Its product of digits (1008) is a multiple of the sum of its prime factors (56).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (91873) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 3154 + ... + 3182.

It is an arithmetic number, because the mean of its divisors is an integer number (4095).

2⁹¹⁸⁷² is an apocalyptic number.

91872 is the 192-nd heptagonal number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 91872, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (147420).

91872 is an abundant number, since it is smaller than the sum of its proper divisors (202968).

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

91872 is a wasteful number, since it uses less digits than its factorization.

91872 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 56 (or 45 counting only the distinct ones).

The product of its digits is 1008, while the sum is 27.

The square root of 91872 is about 303.1039425676. The cubic root of 91872 is about 45.1226284873.

It can be divided in two parts, 918 and 72, that added together give a triangular number (990 = T₄₄).

The spelling of 91872 in words is "ninety-one thousand, eight hundred seventy-two".