671697685 has 16 divisors (see below), whose sum is σ = 816430320. Its totient is φ = 530449920.

The previous prime is 671697683. The next prime is 671697703. The reversal of 671697685 is 586796176.

It can be written as a sum of positive squares in 8 ways, for example, as 3526884 + 668170801 = 1878^2 + 25849^2 .

It is not a de Polignac number, because 671697685 - 2¹ = 671697683 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (671697683) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 485695 + ... + 487075.

It is an arithmetic number, because the mean of its divisors is an integer number (51026895).

Almost surely, 2^671697685 is an apocalyptic number.

It is an amenable number.

671697685 is a deficient number, since it is larger than the sum of its proper divisors (144732635).

671697685 is a wasteful number, since it uses less digits than its factorization.

671697685 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2568.

The product of its digits is 3810240, while the sum is 55.

The square root of 671697685 is about 25917.1311105222. The cubic root of 671697685 is about 875.7724596322.

It can be divided in two parts, 6716 and 97685, that added together give a palindrome (104401).

The spelling of 671697685 in words is "six hundred seventy-one million, six hundred ninety-seven thousand, six hundred eighty-five".