685735289 has 4 divisors (see below), whose sum is σ = 721826640. Its totient is φ = 649643940.

The previous prime is 685735277. The next prime is 685735339. The reversal of 685735289 is 982537586.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4, and also an emirpimes, since its reverse is a distinct semiprime: 982537586 = 2 ⋅491268793.

It is a cyclic number.

It is not a de Polignac number, because 685735289 - 2⁸ = 685735033 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is a self number, because there is not a number n which added to its sum of digits gives 685735289.

It is not an unprimeable number, because it can be changed into a prime (685735249) 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, 18045647 + ... + 18045684.

It is an arithmetic number, because the mean of its divisors is an integer number (180456660).

Almost surely, 2^685735289 is an apocalyptic number.

It is an amenable number.

685735289 is a deficient number, since it is larger than the sum of its proper divisors (36091351).

685735289 is a wasteful number, since it uses less digits than its factorization.

685735289 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 36091350.

The product of its digits is 3628800, while the sum is 53.

The square root of 685735289 is about 26186.5478633592. The cubic root of 685735289 is about 881.8312798690.

The spelling of 685735289 in words is "six hundred eighty-five million, seven hundred thirty-five thousand, two hundred eighty-nine".