686041672721 has 16 divisors (see below), whose sum is σ = 764780924160. Its totient is φ = 611580844800.

The previous prime is 686041672691. The next prime is 686041672733. The reversal of 686041672721 is 127276140686.

686041672721 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-686041672721 is a prime.

It is a super-3 number, since 3×686041672721³ (a number of 36 digits) contains 333 as substring.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 686041672721.

It is not an unprimeable number, because it can be changed into a prime (686041677721) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 1430696 + ... + 1849046.

It is an arithmetic number, because the mean of its divisors is an integer number (47798807760).

Almost surely, 2^686041672721 is an apocalyptic number.

It is an amenable number.

686041672721 is a deficient number, since it is larger than the sum of its proper divisors (78739251439).

686041672721 is a wasteful number, since it uses less digits than its factorization.

686041672721 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 423464.

The product of its (nonzero) digits is 1354752, while the sum is 50.

The spelling of 686041672721 in words is "six hundred eighty-six billion, forty-one million, six hundred seventy-two thousand, seven hundred twenty-one".