91581378 has 48 divisors (see below), whose sum is σ = 216394560. Its totient is φ = 25310880.

The previous prime is 91581367. The next prime is 91581433. The reversal of 91581378 is 87318519.

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

It is an unprimeable number.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 39228 + ... + 41496.

It is an arithmetic number, because the mean of its divisors is an integer number (4508220).

Almost surely, 2^91581378 is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 91581378, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (108197280).

91581378 is an abundant number, since it is smaller than the sum of its proper divisors (124813182).

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

91581378 is a wasteful number, since it uses less digits than its factorization.

91581378 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2343 (or 2312 counting only the distinct ones).

The product of its digits is 60480, while the sum is 42.

The square root of 91581378 is about 9569.8159856917. The cubic root of 91581378 is about 450.7499888489.

The spelling of 91581378 in words is "ninety-one million, five hundred eighty-one thousand, three hundred seventy-eight".