91801440 has 144 divisors (see below), whose sum is σ = 321925968. Its totient is φ = 23804928.

The previous prime is 91801439. The next prime is 91801519. The reversal of 91801440 is 4410819.

It is a tau number, because it is divible by the number of its divisors (144).

It is a congruent number.

It is an unprimeable number.

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 23 ways as a sum of consecutive naturals, for example, 52419 + ... + 54141.

It is an arithmetic number, because the mean of its divisors is an integer number (2235597).

Almost surely, 2^91801440 is an apocalyptic number.

91801440 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 91801440, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (160962984).

91801440 is an abundant number, since it is smaller than the sum of its proper divisors (230124528).

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

91801440 is a wasteful number, since it uses less digits than its factorization.

91801440 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1781 (or 1770 counting only the distinct ones).

The product of its (nonzero) digits is 1152, while the sum is 27.

The square root of 91801440 is about 9581.3068002230. The cubic root of 91801440 is about 451.1107375858.

The spelling of 91801440 in words is "ninety-one million, eight hundred one thousand, four hundred forty".