91228388 has 12 divisors (see below), whose sum is σ = 160258560. Its totient is φ = 45440232.

The previous prime is 91228387. The next prime is 91228393. The reversal of 91228388 is 88382219.

It is a happy number.

It is not an unprimeable number, because it can be changed into a prime (91228387) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 42308 + ... + 44411.

It is an arithmetic number, because the mean of its divisors is an integer number (13354880).

Almost surely, 2^91228388 is an apocalyptic number.

It is an amenable number.

91228388 is a deficient number, since it is larger than the sum of its proper divisors (69030172).

91228388 is a wasteful number, since it uses less digits than its factorization.

91228388 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 86986 (or 86984 counting only the distinct ones).

The product of its digits is 55296, while the sum is 41.

The square root of 91228388 is about 9551.3552965011. The cubic root of 91228388 is about 450.1701216859.

The spelling of 91228388 in words is "ninety-one million, two hundred twenty-eight thousand, three hundred eighty-eight".