671986765 has 16 divisors (see below), whose sum is σ = 811688832. Its totient is φ = 534066624.

The previous prime is 671986739. The next prime is 671986769. The reversal of 671986765 is 567689176.

It is a cyclic number.

It is not a de Polignac number, because 671986765 - 2²⁹ = 135115853 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 (671986769) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 757152 + ... + 758038.

It is an arithmetic number, because the mean of its divisors is an integer number (50730552).

Almost surely, 2^671986765 is an apocalyptic number.

It is an amenable number.

671986765 is a deficient number, since it is larger than the sum of its proper divisors (139702067).

671986765 is a wasteful number, since it uses less digits than its factorization.

671986765 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1716.

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

The square root of 671986765 is about 25922.7075167699. The cubic root of 671986765 is about 875.8980776486.

The spelling of 671986765 in words is "six hundred seventy-one million, nine hundred eighty-six thousand, seven hundred sixty-five".