678733765609 has 9 divisors (see below), whose sum is σ = 683767236477. Its totient is φ = 673737097164.

The previous prime is 678733765561. The next prime is 678733765627. The reversal of 678733765609 is 906567337876.

The square root of 678733765609 is 823853.

It is a perfect power (a square), and thus also a powerful number.

It is not a de Polignac number, because 678733765609 - 2³¹ = 676586281961 is a prime.

It is a super-2 number, since 2×678733765609² (a number of 24 digits) contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (678733765109) by changing a digit.

It is a polite number, since it can be written in 8 ways as a sum of consecutive naturals, for example, 114512604 + ... + 114518530.

Almost surely, 2^678733765609 is an apocalyptic number.

678733765609 is the 823853-rd square number.

678733765609 is the 411927-th centered octagonal number.

It is an amenable number.

678733765609 is a deficient number, since it is larger than the sum of its proper divisors (5033470868).

678733765609 is an frugal number, since it uses more digits than its factorization.

678733765609 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 12132 (or 6066 counting only the distinct ones).

The product of its (nonzero) digits is 240045120, while the sum is 67.

The spelling of 678733765609 in words is "six hundred seventy-eight billion, seven hundred thirty-three million, seven hundred sixty-five thousand, six hundred nine".