91161000 has 192 divisors, whose sum is σ = 352385280. Its totient is φ = 20822400.

The previous prime is 91160969. The next prime is 91161019. The reversal of 91161000 is 16119.

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

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, 62277 + ... + 63723.

It is an arithmetic number, because the mean of its divisors is an integer number (1835340).

Almost surely, 2^91161000 is an apocalyptic number.

91161000 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 91161000, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (176192640).

91161000 is an abundant number, since it is smaller than the sum of its proper divisors (261224280).

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

91161000 is a wasteful number, since it uses less digits than its factorization.

91161000 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1481 (or 1464 counting only the distinct ones).

The product of its (nonzero) digits is 54, while the sum is 18.

The square root of 91161000 is about 9547.8269779044. The cubic root of 91161000 is about 450.0592514573.

Adding to 91161000 its reverse (16119), we get a palindrome (91177119).

The spelling of 91161000 in words is "ninety-one million, one hundred sixty-one thousand".