678481409 has 4 divisors (see below), whose sum is σ = 678649860. Its totient is φ = 678312960.

The previous prime is 678481399. The next prime is 678481411. The reversal of 678481409 is 904184876.

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 160782400 + 517699009 = 12680^2 + 22753^2 .

It is a cyclic number.

It is not a de Polignac number, because 678481409 - 2²⁸ = 410045953 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (678481459) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 78032 + ... + 86289.

It is an arithmetic number, because the mean of its divisors is an integer number (169662465).

Almost surely, 2^678481409 is an apocalyptic number.

It is an amenable number.

678481409 is a deficient number, since it is larger than the sum of its proper divisors (168451).

678481409 is a wasteful number, since it uses less digits than its factorization.

678481409 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 168450.

The product of its (nonzero) digits is 387072, while the sum is 47.

The square root of 678481409 is about 26047.6756928521. The cubic root of 678481409 is about 878.7108400648.

The spelling of 678481409 in words is "six hundred seventy-eight million, four hundred eighty-one thousand, four hundred nine".