91788861 has 16 divisors (see below), whose sum is σ = 128227328. Its totient is φ = 58330800.

The previous prime is 91788859. The next prime is 91788877. The reversal of 91788861 is 16888719.

It is not a de Polignac number, because 91788861 - 2¹ = 91788859 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 91788861.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (91788811) 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, 1135 + ... + 13596.

It is an arithmetic number, because the mean of its divisors is an integer number (8014208).

Almost surely, 2^91788861 is an apocalyptic number.

It is an amenable number.

91788861 is a deficient number, since it is larger than the sum of its proper divisors (36438467).

91788861 is a wasteful number, since it uses less digits than its factorization.

91788861 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 14832.

The product of its digits is 193536, while the sum is 48.

The square root of 91788861 is about 9580.6503432700. The cubic root of 91788861 is about 451.0901323129.

The spelling of 91788861 in words is "ninety-one million, seven hundred eighty-eight thousand, eight hundred sixty-one".