91218120 has 192 divisors, whose sum is σ = 326021760. Its totient is φ = 19998720.

The previous prime is 91218109. The next prime is 91218143. The reversal of 91218120 is 2181219.

It is a Harshad number since it is a multiple of its sum of digits (24).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 807184 + ... + 807296.

It is an arithmetic number, because the mean of its divisors is an integer number (1698030).

Almost surely, 2^91218120 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 91218120, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (163010880).

91218120 is an abundant number, since it is smaller than the sum of its proper divisors (234803640).

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

91218120 is a wasteful number, since it uses less digits than its factorization.

91218120 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 196 (or 161 counting only the distinct ones).

The product of its (nonzero) digits is 288, while the sum is 24.

The square root of 91218120 is about 9550.8177660345. The cubic root of 91218120 is about 450.1532317670.

Adding to 91218120 its reverse (2181219), we get a palindrome (93399339).

The spelling of 91218120 in words is "ninety-one million, two hundred eighteen thousand, one hundred twenty".