679384765505 has 4 divisors (see below), whose sum is σ = 815261718612. Its totient is φ = 543507812400.

The previous prime is 679384765489. The next prime is 679384765511. The reversal of 679384765505 is 505567483976.

679384765505 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a Cunningham number, because it is equal to 824248²+1.

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

It can be written as a sum of positive squares in 2 ways, for example, as 244577724304 + 434807041201 = 494548^2 + 659399^2 .

It is not a de Polignac number, because 679384765505 - 2⁴ = 679384765489 is a prime.

It is a Duffinian number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 67938476546 + ... + 67938476555.

It is an arithmetic number, because the mean of its divisors is an integer number (203815429653).

Almost surely, 2^679384765505 is an apocalyptic number.

It is an amenable number.

679384765505 is a deficient number, since it is larger than the sum of its proper divisors (135876953107).

679384765505 is a wasteful number, since it uses less digits than its factorization.

679384765505 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 135876953106.

The product of its (nonzero) digits is 190512000, while the sum is 65.

The spelling of 679384765505 in words is "six hundred seventy-nine billion, three hundred eighty-four million, seven hundred sixty-five thousand, five hundred five".