91085490 has 96 divisors (see below), whose sum is σ = 257690160. Its totient is φ = 22228992.

The previous prime is 91085461. The next prime is 91085503. The reversal of 91085490 is 9458019.

91085490 is a `hidden beast` number, since 9 + 108 + 549 + 0 = 666.

It can be written as a sum of positive squares in 8 ways, for example, as 88679889 + 2405601 = 9417^2 + 1551^2 .

It is a Curzon 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, 55806 + ... + 57414.

Almost surely, 2^91085490 is an apocalyptic number.

91085490 is a gapful number since it is divisible by the number (90) formed by its first and last digit.

It is a practical number, because each smaller number is the sum of distinct divisors of 91085490, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (128845080).

91085490 is an abundant number, since it is smaller than the sum of its proper divisors (166604670).

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

91085490 is a wasteful number, since it uses less digits than its factorization.

91085490 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1676 (or 1673 counting only the distinct ones).

The product of its (nonzero) digits is 12960, while the sum is 36.

The square root of 91085490 is about 9543.8718558036. The cubic root of 91085490 is about 449.9349535611.

The spelling of 91085490 in words is "ninety-one million, eighty-five thousand, four hundred ninety".