91800000 has 336 divisors, whose sum is σ = 357164640. Its totient is φ = 23040000.

The previous prime is 91799999. The next prime is 91800019. The reversal of 91800000 is 819.

It is a hoax number, since the sum of its digits (18) coincides with the sum of the digits of its distinct prime factors.

It is a Harshad number since it is a multiple of its sum of digits (18).

It is a super Niven number, because it is divisible the sum of any subset of its (nonzero) digits.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 5399992 + ... + 5400008.

It is an arithmetic number, because the mean of its divisors is an integer number (1062990).

Almost surely, 2^91800000 is an apocalyptic number.

91800000 is a gapful number since it is divisible by the number (90) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 91800000, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (178582320).

91800000 is an abundant number, since it is smaller than the sum of its proper divisors (265364640).

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

91800000 is an equidigital number, since it uses as much as digits as its factorization.

91800000 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 63 (or 27 counting only the distinct ones).

The product of its (nonzero) digits is 72, while the sum is 18.

The square root of 91800000 is about 9581.2316536028. The cubic root of 91800000 is about 451.1083788615.

Adding to 91800000 its reverse (819), we get a palindrome (91800819).

The spelling of 91800000 in words is "ninety-one million, eight hundred thousand".