661186224171 has 30 divisors (see below), whose sum is σ = 1077528216996. Its totient is φ = 400704213600.

The previous prime is 661186224157. The next prime is 661186224229. The reversal of 661186224171 is 171422681166.

661186224171 is a `hidden beast` number, since 6 + 6 + 1 + 1 + 8 + 622 + 4 + 17 + 1 = 666.

It is a de Polignac number, because none of the positive numbers 2^k-661186224171 is a prime.

It is not an unprimeable number, because it can be changed into a prime (661186234171) by changing a digit.

It is a polite number, since it can be written in 29 ways as a sum of consecutive naturals, for example, 24258111 + ... + 24285351.

Almost surely, 2^661186224171 is an apocalyptic number.

661186224171 is a deficient number, since it is larger than the sum of its proper divisors (416341992825).

661186224171 is an frugal number, since it uses more digits than its factorization.

661186224171 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 54505 (or 27255 counting only the distinct ones).

The product of its digits is 193536, while the sum is 45.

The spelling of 661186224171 in words is "six hundred sixty-one billion, one hundred eighty-six million, two hundred twenty-four thousand, one hundred seventy-one".