91865440 has 24 divisors (see below), whose sum is σ = 217032480. Its totient is φ = 36746112.

The previous prime is 91865429. The next prime is 91865441. The reversal of 91865440 is 4456819.

It is a happy number.

It is a self number, because there is not a number n which added to its sum of digits gives 91865440.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (91865441) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 286920 + ... + 287239.

It is an arithmetic number, because the mean of its divisors is an integer number (9043020).

Almost surely, 2^91865440 is an apocalyptic number.

It is an amenable number.

91865440 is an abundant number, since it is smaller than the sum of its proper divisors (125167040).

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

91865440 is a wasteful number, since it uses less digits than its factorization.

91865440 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 574174 (or 574166 counting only the distinct ones).

The product of its (nonzero) digits is 34560, while the sum is 37.

The square root of 91865440 is about 9584.6460550195. The cubic root of 91865440 is about 451.2155448763.

The spelling of 91865440 in words is "ninety-one million, eight hundred sixty-five thousand, four hundred forty".