685669747 has 4 divisors (see below), whose sum is σ = 783622576. Its totient is φ = 587716920.

The previous prime is 685669741. The next prime is 685669763. The reversal of 685669747 is 747966586.

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: 747966586 = 2 ⋅373983293.

It is not a de Polignac number, because 685669747 - 2¹¹ = 685667699 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 685669691 and 685669700.

It is not an unprimeable number, because it can be changed into a prime (685669741) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 48976404 + ... + 48976417.

It is an arithmetic number, because the mean of its divisors is an integer number (195905644).

Almost surely, 2^685669747 is an apocalyptic number.

685669747 is a deficient number, since it is larger than the sum of its proper divisors (97952829).

685669747 is an equidigital number, since it uses as much as digits as its factorization.

685669747 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 97952828.

The product of its digits is 15240960, while the sum is 58.

The square root of 685669747 is about 26185.2963893862. The cubic root of 685669747 is about 881.8031840775.

The spelling of 685669747 in words is "six hundred eighty-five million, six hundred sixty-nine thousand, seven hundred forty-seven".