91404640 has 24 divisors (see below), whose sum is σ = 215943840. Its totient is φ = 36561792.

The previous prime is 91404617. The next prime is 91404641. The reversal of 91404640 is 4640419.

It is a junction number, because it is equal to n+sod(n) for n = 91404599 and 91404608.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (91404641) by changing a digit.

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 3 ways as a sum of consecutive naturals, for example, 285480 + ... + 285799.

It is an arithmetic number, because the mean of its divisors is an integer number (8997660).

Almost surely, 2^91404640 is an apocalyptic number.

It is an amenable number.

91404640 is an abundant number, since it is smaller than the sum of its proper divisors (124539200).

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

91404640 is a wasteful number, since it uses less digits than its factorization.

91404640 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 571294 (or 571286 counting only the distinct ones).

The product of its (nonzero) digits is 3456, while the sum is 28.

The square root of 91404640 is about 9560.5773884217. The cubic root of 91404640 is about 450.4598426965.

The spelling of 91404640 in words is "ninety-one million, four hundred four thousand, six hundred forty".