91099800 has 288 divisors, whose sum is σ = 344710080. Its totient is φ = 21369600.

The previous prime is 91099783. The next prime is 91099807. The reversal of 91099800 is 899019.

It is a Harshad number since it is a multiple of its sum of digits (36).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (91099807) by changing a digit.

It is a polite number, since it can be written in 71 ways as a sum of consecutive naturals, for example, 851347 + ... + 851453.

It is an arithmetic number, because the mean of its divisors is an integer number (1196910).

Almost surely, 2^91099800 is an apocalyptic number.

91099800 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 91099800, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (172355040).

91099800 is an abundant number, since it is smaller than the sum of its proper divisors (253610280).

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

91099800 is a wasteful number, since it uses less digits than its factorization.

91099800 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 183 (or 171 counting only the distinct ones).

The product of its (nonzero) digits is 5832, while the sum is 36.

The square root of 91099800 is about 9544.6215220930. The cubic root of 91099800 is about 449.9585146941.

The spelling of 91099800 in words is "ninety-one million, ninety-nine thousand, eight hundred".