671389191 has 18 divisors (see below), whose sum is σ = 1065963080. Its totient is φ = 406901880.

The previous prime is 671389141. The next prime is 671389193. The reversal of 671389191 is 191983176.

It is not a de Polignac number, because 671389191 - 2¹⁸ = 671127047 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (671389193) by changing a digit.

It is a polite number, since it can be written in 17 ways as a sum of consecutive naturals, for example, 307171 + ... + 309348.

Almost surely, 2^671389191 is an apocalyptic number.

671389191 is a deficient number, since it is larger than the sum of its proper divisors (394573889).

671389191 is a wasteful number, since it uses less digits than its factorization.

671389191 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 616547 (or 616533 counting only the distinct ones).

The product of its digits is 81648, while the sum is 45.

The square root of 671389191 is about 25911.1788809386. The cubic root of 671389191 is about 875.6383656161.

The spelling of 671389191 in words is "six hundred seventy-one million, three hundred eighty-nine thousand, one hundred ninety-one".