685185577 has 4 divisors (see below), whose sum is σ = 685249236. Its totient is φ = 685121920.

The previous prime is 685185547. The next prime is 685185583. The reversal of 685185577 is 775581586.

It is a happy number.

It is a semiprime because it is the product of two primes, and also a brilliant number, because the two primes have the same length.

It can be written as a sum of positive squares in 2 ways, for example, as 144576576 + 540609001 = 12024^2 + 23251^2 .

It is a cyclic number.

It is not a de Polignac number, because 685185577 - 2²⁷ = 550967849 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (685185517) 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, 11248 + ... + 38689.

It is an arithmetic number, because the mean of its divisors is an integer number (171312309).

Almost surely, 2^685185577 is an apocalyptic number.

It is an amenable number.

685185577 is a deficient number, since it is larger than the sum of its proper divisors (63659).

685185577 is a wasteful number, since it uses less digits than its factorization.

685185577 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 63658.

The product of its digits is 2352000, while the sum is 52.

The square root of 685185577 is about 26176.0496828685. The cubic root of 685185577 is about 881.5955801589.

The spelling of 685185577 in words is "six hundred eighty-five million, one hundred eighty-five thousand, five hundred seventy-seven".