684121105 has 4 divisors (see below), whose sum is σ = 820945332. Its totient is φ = 547296880.

The previous prime is 684121079. The next prime is 684121147. The reversal of 684121105 is 501121486.

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 149401729 + 534719376 = 12223^2 + 23124^2 .

It is not a de Polignac number, because 684121105 - 2⁷ = 684120977 is a prime.

It is a Duffinian number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 68412106 + ... + 68412115.

It is an arithmetic number, because the mean of its divisors is an integer number (205236333).

Almost surely, 2^684121105 is an apocalyptic number.

It is an amenable number.

684121105 is a deficient number, since it is larger than the sum of its proper divisors (136824227).

684121105 is a wasteful number, since it uses less digits than its factorization.

684121105 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 136824226.

The product of its (nonzero) digits is 1920, while the sum is 28.

The square root of 684121105 is about 26155.7088414747. The cubic root of 684121105 is about 881.1388084313.

The spelling of 684121105 in words is "six hundred eighty-four million, one hundred twenty-one thousand, one hundred five".