678745679 has 4 divisors (see below), whose sum is σ = 678817584. Its totient is φ = 678673776.

The previous prime is 678745673. The next prime is 678745703. The reversal of 678745679 is 976547876.

It is a semiprime because it is the product of two primes, and also a brilliant number, because the two primes have the same length.

It is a cyclic number.

It is not a de Polignac number, because 678745679 - 2⁸ = 678745423 is a prime.

It is a super-2 number, since 2×678745679² = 921391393522342082, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (678745673) 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, 19187 + ... + 41540.

It is an arithmetic number, because the mean of its divisors is an integer number (169704396).

Almost surely, 2^678745679 is an apocalyptic number.

678745679 is a deficient number, since it is larger than the sum of its proper divisors (71905).

678745679 is a wasteful number, since it uses less digits than its factorization.

678745679 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 71904.

The product of its digits is 17781120, while the sum is 59.

The square root of 678745679 is about 26052.7480124458. The cubic root of 678745679 is about 878.8249118568.

The spelling of 678745679 in words is "six hundred seventy-eight million, seven hundred forty-five thousand, six hundred seventy-nine".