91749888 has 80 divisors (see below), whose sum is σ = 271626960. Its totient is φ = 30578688.

The previous prime is 91749887. The next prime is 91749907. The reversal of 91749888 is 88894719.

It is a Harshad number since it is a multiple of its sum of digits (54).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (91749883) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 10506 + ... + 17142.

It is an arithmetic number, because the mean of its divisors is an integer number (3395337).

Almost surely, 2^91749888 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 91749888, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (135813480).

91749888 is an abundant number, since it is smaller than the sum of its proper divisors (179877072).

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

91749888 is an equidigital number, since it uses as much as digits as its factorization.

91749888 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 6664 (or 6642 counting only the distinct ones).

The product of its digits is 1161216, while the sum is 54.

The square root of 91749888 is about 9578.6161839798. The cubic root of 91749888 is about 451.0262798865.

It can be divided in two parts, 917 and 49888, that added together give a palindrome (50805).

The spelling of 91749888 in words is "ninety-one million, seven hundred forty-nine thousand, eight hundred eighty-eight".