91089640 has 32 divisors (see below), whose sum is σ = 205274880. Its totient is φ = 36378432.

The previous prime is 91089623. The next prime is 91089641. The reversal of 91089640 is 4698019.

It is a self number, because there is not a number n which added to its sum of digits gives 91089640.

It is not an unprimeable number, because it can be changed into a prime (91089641) 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, 31537 + ... + 34303.

It is an arithmetic number, because the mean of its divisors is an integer number (6414840).

Almost surely, 2^91089640 is an apocalyptic number.

It is an amenable number.

91089640 is an abundant number, since it is smaller than the sum of its proper divisors (114185240).

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

91089640 is a wasteful number, since it uses less digits than its factorization.

91089640 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3601 (or 3597 counting only the distinct ones).

The product of its (nonzero) digits is 15552, while the sum is 37.

The square root of 91089640 is about 9544.0892703285. The cubic root of 91089640 is about 449.9417867084.

The spelling of 91089640 in words is "ninety-one million, eighty-nine thousand, six hundred forty".