684338905 has 4 divisors (see below), whose sum is σ = 821206692. Its totient is φ = 547471120.

The previous prime is 684338899. The next prime is 684338917. The reversal of 684338905 is 509833486.

684338905 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.

It can be written as a sum of positive squares in 2 ways, for example, as 297666009 + 386672896 = 17253^2 + 19664^2 .

It is not a de Polignac number, because 684338905 - 2²¹ = 682241753 is a prime.

It is a Duffinian number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 68433886 + ... + 68433895.

It is an arithmetic number, because the mean of its divisors is an integer number (205301673).

Almost surely, 2^684338905 is an apocalyptic number.

It is an amenable number.

684338905 is a deficient number, since it is larger than the sum of its proper divisors (136867787).

684338905 is a wasteful number, since it uses less digits than its factorization.

684338905 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 136867786.

The product of its (nonzero) digits is 622080, while the sum is 46.

The square root of 684338905 is about 26159.8720371488. The cubic root of 684338905 is about 881.2323063362.

The spelling of 684338905 in words is "six hundred eighty-four million, three hundred thirty-eight thousand, nine hundred five".