686704505 has 4 divisors (see below), whose sum is σ = 824045412. Its totient is φ = 549363600.

The previous prime is 686704471. The next prime is 686704519. The reversal of 686704505 is 505407686.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 422836969 + 263867536 = 20563^2 + 16244^2 .

It is not a de Polignac number, because 686704505 - 2²² = 682510201 is a prime.

It is a Duffinian number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 68670446 + ... + 68670455.

It is an arithmetic number, because the mean of its divisors is an integer number (206011353).

Almost surely, 2^686704505 is an apocalyptic number.

It is an amenable number.

686704505 is a deficient number, since it is larger than the sum of its proper divisors (137340907).

686704505 is a wasteful number, since it uses less digits than its factorization.

686704505 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 137340906.

The product of its (nonzero) digits is 201600, while the sum is 41.

The square root of 686704505 is about 26205.0473191712. The cubic root of 686704505 is about 882.2465434290.

The spelling of 686704505 in words is "six hundred eighty-six million, seven hundred four thousand, five hundred five".