678635579 has 4 divisors (see below), whose sum is σ = 679518840. Its totient is φ = 677752320.

The previous prime is 678635561. The next prime is 678635593. The reversal of 678635579 is 975536876.

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

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-678635579 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (678635519) 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, 440477 + ... + 442014.

It is an arithmetic number, because the mean of its divisors is an integer number (169879710).

Almost surely, 2^678635579 is an apocalyptic number.

678635579 is a deficient number, since it is larger than the sum of its proper divisors (883261).

678635579 is an equidigital number, since it uses as much as digits as its factorization.

678635579 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 883260.

The product of its digits is 9525600, while the sum is 56.

The square root of 678635579 is about 26050.6349058905. The cubic root of 678635579 is about 878.7773909379. Note that the first 3 decimals are identical.

The spelling of 678635579 in words is "six hundred seventy-eight million, six hundred thirty-five thousand, five hundred seventy-nine".