91641555 has 12 divisors (see below), whose sum is σ = 158845440. Its totient is φ = 48875472.

The previous prime is 91641547. The next prime is 91641607. The reversal of 91641555 is 55514619.

91641555 is a `hidden beast` number, since 9 + 1 + 641 + 5 + 5 + 5 = 666.

It is not a de Polignac number, because 91641555 - 2³ = 91641547 is a prime.

It is an unprimeable number.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 1018195 + ... + 1018284.

It is an arithmetic number, because the mean of its divisors is an integer number (13237120).

Almost surely, 2^91641555 is an apocalyptic number.

91641555 is a deficient number, since it is larger than the sum of its proper divisors (67203885).

91641555 is a wasteful number, since it uses less digits than its factorization.

91641555 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2036490 (or 2036487 counting only the distinct ones).

The product of its digits is 27000, while the sum is 36.

The square root of 91641555 is about 9572.9595737160. The cubic root of 91641555 is about 450.8486946620.

The spelling of 91641555 in words is "ninety-one million, six hundred forty-one thousand, five hundred fifty-five".