671239687 has 2 divisors, whose sum is σ = 671239688. Its totient is φ = 671239686.

The previous prime is 671239661. The next prime is 671239703. The reversal of 671239687 is 786932176.

It is a happy number.

It is a strong prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-671239687 is a prime.

It is a Chen prime.

It is equal to p_34839499 and since 671239687 and 34839499 have the same sum of digits, it is a Honaker prime.

It is a self number, because there is not a number n which added to its sum of digits gives 671239687.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (671239787) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 335619843 + 335619844.

It is an arithmetic number, because the mean of its divisors is an integer number (335619844).

Almost surely, 2^671239687 is an apocalyptic number.

671239687 is a deficient number, since it is larger than the sum of its proper divisors (1).

671239687 is an equidigital number, since it uses as much as digits as its factorization.

671239687 is an evil number, because the sum of its binary digits is even.

The product of its digits is 762048, while the sum is 49.

The square root of 671239687 is about 25908.2937878973. The cubic root of 671239687 is about 875.5733654849.

The spelling of 671239687 in words is "six hundred seventy-one million, two hundred thirty-nine thousand, six hundred eighty-seven".