686393729 has 4 divisors (see below), whose sum is σ = 784449984. Its totient is φ = 588337476.

The previous prime is 686393713. The next prime is 686393731. The reversal of 686393729 is 927393686.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 686393729 - 2⁴ = 686393713 is a prime.

It is a super-2 number, since 2×686393729² = 942272702421050882, which contains 22 as substring.

It is a Duffinian number.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (686393749) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 49028117 + ... + 49028130.

It is an arithmetic number, because the mean of its divisors is an integer number (196112496).

Almost surely, 2^686393729 is an apocalyptic number.

It is an amenable number.

686393729 is a deficient number, since it is larger than the sum of its proper divisors (98056255).

686393729 is an equidigital number, since it uses as much as digits as its factorization.

686393729 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 98056254.

The product of its digits is 2939328, while the sum is 53.

The square root of 686393729 is about 26199.1169507676. The cubic root of 686393729 is about 882.1134330827.

The spelling of 686393729 in words is "six hundred eighty-six million, three hundred ninety-three thousand, seven hundred twenty-nine".