685197655 has 4 divisors (see below), whose sum is σ = 822237192. Its totient is φ = 548158120.

The previous prime is 685197629. The next prime is 685197659. The reversal of 685197655 is 556791586.

It is a semiprime because it is the product of two primes.

It is a de Polignac number, because none of the positive numbers 2^k-685197655 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (685197659) 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, 68519761 + ... + 68519770.

It is an arithmetic number, because the mean of its divisors is an integer number (205559298).

Almost surely, 2^685197655 is an apocalyptic number.

685197655 is a deficient number, since it is larger than the sum of its proper divisors (137039537).

685197655 is a wasteful number, since it uses less digits than its factorization.

685197655 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 137039536.

The product of its digits is 2268000, while the sum is 52.

The square root of 685197655 is about 26176.2803889323. The cubic root of 685197655 is about 881.6007601905.

The spelling of 685197655 in words is "six hundred eighty-five million, one hundred ninety-seven thousand, six hundred fifty-five".