686720347 has 4 divisors (see below), whose sum is σ = 686984976. Its totient is φ = 686455720.

The previous prime is 686720341. The next prime is 686720393. The reversal of 686720347 is 743027686.

It is a happy number.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 743027686 = 2 ⋅371513843.

It is a cyclic number.

It is not a de Polignac number, because 686720347 - 2¹⁹ = 686196059 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (686720341) 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, 128383 + ... + 133624.

It is an arithmetic number, because the mean of its divisors is an integer number (171746244).

Almost surely, 2^686720347 is an apocalyptic number.

686720347 is a deficient number, since it is larger than the sum of its proper divisors (264629).

686720347 is a wasteful number, since it uses less digits than its factorization.

686720347 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 264628.

The product of its (nonzero) digits is 338688, while the sum is 43.

The square root of 686720347 is about 26205.3495874411. The cubic root of 686720347 is about 882.2533277359.

The spelling of 686720347 in words is "six hundred eighty-six million, seven hundred twenty thousand, three hundred forty-seven".