91228660 has 48 divisors (see below), whose sum is σ = 198858240. Its totient is φ = 35118720.

The previous prime is 91228639. The next prime is 91228759. The reversal of 91228660 is 6682219.

It is a happy number.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 166507 + ... + 167053.

It is an arithmetic number, because the mean of its divisors is an integer number (4142880).

Almost surely, 2^91228660 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 91228660, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (99429120).

91228660 is an abundant number, since it is smaller than the sum of its proper divisors (107629580).

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

91228660 is a wasteful number, since it uses less digits than its factorization.

91228660 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 856 (or 854 counting only the distinct ones).

The product of its (nonzero) digits is 10368, while the sum is 34.

The square root of 91228660 is about 9551.3695353075. The cubic root of 91228660 is about 450.1705690838.

The spelling of 91228660 in words is "ninety-one million, two hundred twenty-eight thousand, six hundred sixty".