685583993 has 2 divisors, whose sum is σ = 685583994. Its totient is φ = 685583992.

The previous prime is 685583963. The next prime is 685584013. The reversal of 685583993 is 399385586.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 383102329 + 302481664 = 19573^2 + 17392^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-685583993 is a prime.

It is a super-2 number, since 2×685583993² = 940050822915648098, which contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (685583903) by changing a digit.

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 as a sum of consecutive naturals, namely, 342791996 + 342791997.

It is an arithmetic number, because the mean of its divisors is an integer number (342791997).

Almost surely, 2^685583993 is an apocalyptic number.

It is an amenable number.

685583993 is a deficient number, since it is larger than the sum of its proper divisors (1).

685583993 is an equidigital number, since it uses as much as digits as its factorization.

685583993 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 6998400, while the sum is 56.

The square root of 685583993 is about 26183.6588925230. The cubic root of 685583993 is about 881.7664213341.

The spelling of 685583993 in words is "six hundred eighty-five million, five hundred eighty-three thousand, nine hundred ninety-three".