678512399 has 4 divisors (see below), whose sum is σ = 679718136. Its totient is φ = 677306664.

The previous prime is 678512389. The next prime is 678512447. The reversal of 678512399 is 993215876.

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

It is a cyclic number.

It is not a de Polignac number, because 678512399 - 2⁴ = 678512383 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 (678512389) 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, 602024 + ... + 603149.

It is an arithmetic number, because the mean of its divisors is an integer number (169929534).

Almost surely, 2^678512399 is an apocalyptic number.

678512399 is a deficient number, since it is larger than the sum of its proper divisors (1205737).

678512399 is a wasteful number, since it uses less digits than its factorization.

678512399 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1205736.

The product of its digits is 816480, while the sum is 50.

The square root of 678512399 is about 26048.2705567951. The cubic root of 678512399 is about 878.7242183898.

The spelling of 678512399 in words is "six hundred seventy-eight million, five hundred twelve thousand, three hundred ninety-nine".