91253778 has 128 divisors (see below), whose sum is σ = 241920000. Its totient is φ = 22720320.

The previous prime is 91253759. The next prime is 91253791. The reversal of 91253778 is 87735219.

It is a Harshad number since it is a multiple of its sum of digits (42).

It is a Curzon number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 63 ways as a sum of consecutive naturals, for example, 656433 + ... + 656571.

It is an arithmetic number, because the mean of its divisors is an integer number (1890000).

Almost surely, 2^91253778 is an apocalyptic number.

91253778 is a gapful number since it is divisible by the number (98) formed by its first and last digit.

It is a practical number, because each smaller number is the sum of distinct divisors of 91253778, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (120960000).

91253778 is an abundant number, since it is smaller than the sum of its proper divisors (150666222).

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

91253778 is a wasteful number, since it uses less digits than its factorization.

91253778 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 205 (or 191 counting only the distinct ones).

The product of its digits is 105840, while the sum is 42.

The square root of 91253778 is about 9552.6843347826. The cubic root of 91253778 is about 450.2118804683.

The spelling of 91253778 in words is "ninety-one million, two hundred fifty-three thousand, seven hundred seventy-eight".