685566557 has 8 divisors (see below), whose sum is σ = 748702080. Its totient is φ = 623916720.

The previous prime is 685566533. The next prime is 685566613. The reversal of 685566557 is 755665586.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 685566557 - 2¹⁰ = 685565533 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 685566499 and 685566508.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (685566517) 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 in 7 ways as a sum of consecutive naturals, for example, 370457 + ... + 372302.

It is an arithmetic number, because the mean of its divisors is an integer number (93587760).

Almost surely, 2^685566557 is an apocalyptic number.

It is an amenable number.

685566557 is a deficient number, since it is larger than the sum of its proper divisors (63135523).

685566557 is a wasteful number, since it uses less digits than its factorization.

685566557 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 742843.

The product of its digits is 7560000, while the sum is 53.

The square root of 685566557 is about 26183.3259346478. The cubic root of 685566557 is about 881.7589461451.

The spelling of 685566557 in words is "six hundred eighty-five million, five hundred sixty-six thousand, five hundred fifty-seven".