686162721 has 16 divisors (see below), whose sum is σ = 971837568. Its totient is φ = 429139200.

The previous prime is 686162699. The next prime is 686162723. The reversal of 686162721 is 127261686.

It is not a de Polignac number, because 686162721 - 2⁵ = 686162689 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 686162721.

It is not an unprimeable number, because it can be changed into a prime (686162723) 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, 5770 + ... + 37491.

It is an arithmetic number, because the mean of its divisors is an integer number (60739848).

Almost surely, 2^686162721 is an apocalyptic number.

It is an amenable number.

686162721 is a deficient number, since it is larger than the sum of its proper divisors (285674847).

686162721 is a wasteful number, since it uses less digits than its factorization.

686162721 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 43592.

The product of its digits is 48384, while the sum is 39.

The square root of 686162721 is about 26194.7078815550. The cubic root of 686162721 is about 882.0144626153.

The spelling of 686162721 in words is "six hundred eighty-six million, one hundred sixty-two thousand, seven hundred twenty-one".