91284228 has 72 divisors (see below), whose sum is σ = 272825280. Its totient is φ = 25179840.

The previous prime is 91284223. The next prime is 91284229. The reversal of 91284228 is 82248219.

It is a Harshad number since it is a multiple of its sum of digits (36).

It is a junction number, because it is equal to n+sod(n) for n = 91284192 and 91284201.

It is not an unprimeable number, because it can be changed into a prime (91284223) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 1063 + ... + 13553.

It is an arithmetic number, because the mean of its divisors is an integer number (3789240).

Almost surely, 2^91284228 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 91284228, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (136412640).

91284228 is an abundant number, since it is smaller than the sum of its proper divisors (181541052).

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

91284228 is a wasteful number, since it uses less digits than its factorization.

91284228 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 12537 (or 12532 counting only the distinct ones).

The product of its digits is 18432, while the sum is 36.

The square root of 91284228 is about 9554.2779946995. The cubic root of 91284228 is about 450.2619511887.

The spelling of 91284228 in words is "ninety-one million, two hundred eighty-four thousand, two hundred twenty-eight".