91169820 has 192 divisors, whose sum is σ = 329011200. Its totient is φ = 20528640.

The previous prime is 91169803. The next prime is 91169821. The reversal of 91169820 is 2896119.

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 (91169821) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 63 ways as a sum of consecutive naturals, for example, 336285 + ... + 336555.

It is an arithmetic number, because the mean of its divisors is an integer number (1713600).

Almost surely, 2^91169820 is an apocalyptic number.

91169820 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 91169820, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (164505600).

91169820 is an abundant number, since it is smaller than the sum of its proper divisors (237841380).

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

91169820 is a wasteful number, since it uses less digits than its factorization.

91169820 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 385 (or 377 counting only the distinct ones).

The product of its (nonzero) digits is 7776, while the sum is 36.

The square root of 91169820 is about 9548.2888519357. The cubic root of 91169820 is about 450.0737656852.

The spelling of 91169820 in words is "ninety-one million, one hundred sixty-nine thousand, eight hundred twenty".