91866555 has 80 divisors (see below), whose sum is σ = 190374624. Its totient is φ = 41886720.

The previous prime is 91866499. The next prime is 91866557. The reversal of 91866555 is 55566819.

It is a happy number.

91866555 is a `hidden beast` number, since 91 + 8 + 6 + 6 + 555 = 666.

It is not a de Polignac number, because 91866555 - 2⁶ = 91866491 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (45).

It is a self number, because there is not a number n which added to its sum of digits gives 91866555.

It is not an unprimeable number, because it can be changed into a prime (91866557) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 79 ways as a sum of consecutive naturals, for example, 75129 + ... + 76341.

Almost surely, 2^91866555 is an apocalyptic number.

91866555 is an abundant number, since it is smaller than the sum of its proper divisors (98508069).

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

91866555 is a wasteful number, since it uses less digits than its factorization.

91866555 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1258 (or 1249 counting only the distinct ones).

The product of its digits is 324000, while the sum is 45.

The square root of 91866555 is about 9584.7042207885. The cubic root of 91866555 is about 451.2173703843.

The spelling of 91866555 in words is "ninety-one million, eight hundred sixty-six thousand, five hundred fifty-five".