671912181 has 12 divisors (see below), whose sum is σ = 1021621120. Its totient is φ = 424365480.

The previous prime is 671912177. The next prime is 671912183. The reversal of 671912181 is 181219176.

It is not a de Polignac number, because 671912181 - 2² = 671912177 is a prime.

It is a super-2 number, since 2×671912181² = 902931957952353522, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (671912183) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 1964485 + ... + 1964826.

Almost surely, 2^671912181 is an apocalyptic number.

It is an amenable number.

671912181 is a deficient number, since it is larger than the sum of its proper divisors (349708939).

671912181 is a wasteful number, since it uses less digits than its factorization.

671912181 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3929336 (or 3929333 counting only the distinct ones).

The product of its digits is 6048, while the sum is 36.

The square root of 671912181 is about 25921.2688925523. The cubic root of 671912181 is about 875.8656710583.

The spelling of 671912181 in words is "six hundred seventy-one million, nine hundred twelve thousand, one hundred eighty-one".