671328185661 has 24 divisors (see below), whose sum is σ = 1108858846784. Its totient is φ = 383396457600.

The previous prime is 671328185639. The next prime is 671328185669. The reversal of 671328185661 is 166581823176.

It is a happy number.

671328185661 is a `hidden beast` number, since 6 + 71 + 3 + 2 + 8 + 1 + 8 + 566 + 1 = 666.

It is not a de Polignac number, because 671328185661 - 2⁶ = 671328185597 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is a junction number, because it is equal to n+sod(n) for n = 671328185598 and 671328185607.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (671328185669) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 2939740 + ... + 3159861.

Almost surely, 2^671328185661 is an apocalyptic number.

It is an amenable number.

671328185661 is a deficient number, since it is larger than the sum of its proper divisors (437530661123).

671328185661 is a wasteful number, since it uses less digits than its factorization.

671328185661 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 6101361 (or 6101358 counting only the distinct ones).

The product of its digits is 2903040, while the sum is 54.

The spelling of 671328185661 in words is "six hundred seventy-one billion, three hundred twenty-eight million, one hundred eighty-five thousand, six hundred sixty-one".