686686442 has 16 divisors (see below), whose sum is σ = 1121730120. Its totient is φ = 313370112.

The previous prime is 686686397. The next prime is 686686453. The reversal of 686686442 is 244686686.

It can be written as a sum of positive squares in 4 ways, for example, as 183087961 + 503598481 = 13531^2 + 22441^2 .

It is an unprimeable number.

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 7 ways as a sum of consecutive naturals, for example, 146063 + ... + 150690.

Almost surely, 2^686686442 is an apocalyptic number.

686686442 is a deficient number, since it is larger than the sum of its proper divisors (435043678).

686686442 is a wasteful number, since it uses less digits than its factorization.

686686442 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 296857.

The product of its digits is 2654208, while the sum is 50.

The square root of 686686442 is about 26204.7026695591. The cubic root of 686686442 is about 882.2388078558.

The spelling of 686686442 in words is "six hundred eighty-six million, six hundred eighty-six thousand, four hundred forty-two".