91098 has 32 divisors (see below), whose sum is σ = 232320. Its totient is φ = 25920.

The previous prime is 91097. The next prime is 91099. The reversal of 91098 is 89019.

It is an interprime number because it is at equal distance from previous prime (91097) and next prime (91099).

It is a Harshad number since it is a multiple of its sum of digits (27).

It is not an unprimeable number, because it can be changed into a prime (91097) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 258 + ... + 498.

It is an arithmetic number, because the mean of its divisors is an integer number (7260).

2⁹¹⁰⁹⁸ is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 91098, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (116160).

91098 is an abundant number, since it is smaller than the sum of its proper divisors (141222).

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

91098 is a wasteful number, since it uses less digits than its factorization.

91098 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 259 (or 253 counting only the distinct ones).

The product of its (nonzero) digits is 648, while the sum is 27.

The square root of 91098 is about 301.8244522897. The cubic root of 91098 is about 44.9955551165.

Adding to 91098 its sum of digits (27), we get a cube (91125 = 45³).

The spelling of 91098 in words is "ninety-one thousand, ninety-eight".