671612161 has 4 divisors (see below), whose sum is σ = 732667824. Its totient is φ = 610556500.

The previous prime is 671612159. The next prime is 671612173. The reversal of 671612161 is 161216176.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 671612161 - 2¹ = 671612159 is a prime.

It is a Smith number, since the sum of its digits (31) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (671619161) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 30527815 + ... + 30527836.

It is an arithmetic number, because the mean of its divisors is an integer number (183166956).

Almost surely, 2^671612161 is an apocalyptic number.

It is an amenable number.

671612161 is a deficient number, since it is larger than the sum of its proper divisors (61055663).

671612161 is a wasteful number, since it uses less digits than its factorization.

671612161 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 61055662.

The product of its digits is 3024, while the sum is 31.

The square root of 671612161 is about 25915.4811068597. The cubic root of 671612161 is about 875.7352887716.

The spelling of 671612161 in words is "six hundred seventy-one million, six hundred twelve thousand, one hundred sixty-one".