685654765 has 4 divisors (see below), whose sum is σ = 822785724. Its totient is φ = 548523808.

The previous prime is 685654759. The next prime is 685654769. The reversal of 685654765 is 567456586.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 567456586 = 2 ⋅283728293.

It can be written as a sum of positive squares in 2 ways, for example, as 105904681 + 579750084 = 10291^2 + 24078^2 .

It is a cyclic number.

It is not a de Polignac number, because 685654765 - 2⁷ = 685654637 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 (685654769) 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, 68565472 + ... + 68565481.

It is an arithmetic number, because the mean of its divisors is an integer number (205696431).

Almost surely, 2^685654765 is an apocalyptic number.

It is an amenable number.

685654765 is a deficient number, since it is larger than the sum of its proper divisors (137130959).

685654765 is a wasteful number, since it uses less digits than its factorization.

685654765 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 137130958.

The product of its digits is 6048000, while the sum is 52.

The square root of 685654765 is about 26185.0103112449. The cubic root of 685654765 is about 881.7967615144.

The spelling of 685654765 in words is "six hundred eighty-five million, six hundred fifty-four thousand, seven hundred sixty-five".