678633409 has 4 divisors (see below), whose sum is σ = 678710016. Its totient is φ = 678556804.

The previous prime is 678633401. The next prime is 678633427. The reversal of 678633409 is 904336876.

678633409 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4, 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 678633409 - 2³ = 678633401 is a prime.

It is a super-2 number, since 2×678633409² = 921086607621922562, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (678633401) 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, 22969 + ... + 43414.

It is an arithmetic number, because the mean of its divisors is an integer number (169677504).

Almost surely, 2^678633409 is an apocalyptic number.

It is an amenable number.

678633409 is a deficient number, since it is larger than the sum of its proper divisors (76607).

678633409 is a wasteful number, since it uses less digits than its factorization.

678633409 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 76606.

The product of its (nonzero) digits is 653184, while the sum is 46.

The square root of 678633409 is about 26050.5932562005. The cubic root of 678633409 is about 878.7764542796.

The spelling of 678633409 in words is "six hundred seventy-eight million, six hundred thirty-three thousand, four hundred nine".