91381440 has 56 divisors (see below), whose sum is σ = 290139120. Its totient is φ = 24368128.

The previous prime is 91381439. The next prime is 91381513. The reversal of 91381440 is 4418319.

It is a happy number.

It is a Harshad number since it is a multiple of its sum of digits (30).

It is a junction number, because it is equal to n+sod(n) for n = 91381398 and 91381407.

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 7 ways as a sum of consecutive naturals, for example, 46635 + ... + 48554.

Almost surely, 2^91381440 is an apocalyptic number.

It is an amenable number.

91381440 is an abundant number, since it is smaller than the sum of its proper divisors (198757680).

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

91381440 is a wasteful number, since it uses less digits than its factorization.

91381440 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 95209 (or 95199 counting only the distinct ones).

The product of its (nonzero) digits is 3456, while the sum is 30.

The square root of 91381440 is about 9559.3639955805. The cubic root of 91381440 is about 450.4217281009.

Adding to 91381440 its reverse (4418319), we get a palindrome (95799759).

The spelling of 91381440 in words is "ninety-one million, three hundred eighty-one thousand, four hundred forty".