91129220 has 144 divisors (see below), whose sum is σ = 250967808. Its totient is φ = 27498240.

The previous prime is 91129211. The next prime is 91129229. The reversal of 91129220 is 2292119.

It is a happy number.

It is an interprime number because it is at equal distance from previous prime (91129211) and next prime (91129229).

It is a Harshad number since it is a multiple of its sum of digits (26).

It is a self number, because there is not a number n which added to its sum of digits gives 91129220.

It is not an unprimeable number, because it can be changed into a prime (91129229) by changing a digit.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 292865 + ... + 293175.

It is an arithmetic number, because the mean of its divisors is an integer number (1742832).

Almost surely, 2^91129220 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 91129220, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (125483904).

91129220 is an abundant number, since it is smaller than the sum of its proper divisors (159838588).

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

91129220 is a wasteful number, since it uses less digits than its factorization.

91129220 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 370 (or 361 counting only the distinct ones).

The product of its (nonzero) digits is 648, while the sum is 26.

The square root of 91129220 is about 9546.1625798014. The cubic root of 91129220 is about 450.0069463948.

The spelling of 91129220 in words is "ninety-one million, one hundred twenty-nine thousand, two hundred twenty".