91228 has 6 divisors (see below), whose sum is σ = 159656. Its totient is φ = 45612.

The previous prime is 91199. The next prime is 91229. The reversal of 91228 is 82219.

It is a junction number, because it is equal to n+sod(n) for n = 91199 and 91208.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (91229) by changing a digit.

91228 is an untouchable number, because it is not equal to the sum of proper divisors of any number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 11400 + ... + 11407.

2⁹¹²²⁸ is an apocalyptic number.

It is an amenable number.

91228 is a deficient number, since it is larger than the sum of its proper divisors (68428).

91228 is a wasteful number, since it uses less digits than its factorization.

91228 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 22811 (or 22809 counting only the distinct ones).

The product of its digits is 288, while the sum is 22.

The square root of 91228 is about 302.0397324856. The cubic root of 91228 is about 45.0169483485.

Subtracting from 91228 its reverse (82219), we obtain a palindrome (9009).

The spelling of 91228 in words is "ninety-one thousand, two hundred twenty-eight".