671667181 has 8 divisors (see below), whose sum is σ = 687750624. Its totient is φ = 655604880.

The previous prime is 671667169. The next prime is 671667193. The reversal of 671667181 is 181766176.

It is an interprime number because it is at equal distance from previous prime (671667169) and next prime (671667193).

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 671667181 - 2⁵ = 671667149 is a prime.

It is a super-2 number, since 2×671667181² = 902273604064973522, which contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (43).

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (671667121) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 72471 + ... + 81211.

It is an arithmetic number, because the mean of its divisors is an integer number (85968828).

Almost surely, 2^671667181 is an apocalyptic number.

It is an amenable number.

671667181 is a deficient number, since it is larger than the sum of its proper divisors (16083443).

671667181 is a wasteful number, since it uses less digits than its factorization.

671667181 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 10571.

The product of its digits is 84672, while the sum is 43.

The square root of 671667181 is about 25916.5426127792. The cubic root of 671667181 is about 875.7592021960.

It can be divided in two parts, 67166 and 7181, that added together give a palindrome (74347).

The spelling of 671667181 in words is "six hundred seventy-one million, six hundred sixty-seven thousand, one hundred eighty-one".