91223928 has 64 divisors (see below), whose sum is σ = 255052800. Its totient is φ = 30209760.

The previous prime is 91223903. The next prime is 91223929. The reversal of 91223928 is 82932219.

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

It is a nude number because it is divisible by every one of its digits.

It is a junction number, because it is equal to n+sod(n) for n = 91223892 and 91223901.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (91223929) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 33913 + ... + 36503.

It is an arithmetic number, because the mean of its divisors is an integer number (3985200).

Almost surely, 2^91223928 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 91223928, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (127526400).

91223928 is an abundant number, since it is smaller than the sum of its proper divisors (163828872).

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

91223928 is a wasteful number, since it uses less digits than its factorization.

91223928 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2769 (or 2759 counting only the distinct ones).

The product of its digits is 15552, while the sum is 36.

The square root of 91223928 is about 9551.1218189279. The cubic root of 91223928 is about 450.1627855504.

The spelling of 91223928 in words is "ninety-one million, two hundred twenty-three thousand, nine hundred twenty-eight".