91788216 has 64 divisors (see below), whose sum is σ = 257886720. Its totient is φ = 27012480.

The previous prime is 91788211. The next prime is 91788251. The reversal of 91788216 is 61288719.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (91788211) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 781 + ... + 13571.

It is an arithmetic number, because the mean of its divisors is an integer number (4029480).

Almost surely, 2^91788216 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 91788216, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (128943360).

91788216 is an abundant number, since it is smaller than the sum of its proper divisors (166098504).

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

91788216 is a wasteful number, since it uses less digits than its factorization.

91788216 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 12836 (or 12832 counting only the distinct ones).

The product of its digits is 48384, while the sum is 42.

The square root of 91788216 is about 9580.6166816129. The cubic root of 91788216 is about 451.0890757075.

The spelling of 91788216 in words is "ninety-one million, seven hundred eighty-eight thousand, two hundred sixteen".