684212189 has 4 divisors (see below), whose sum is σ = 687148956. Its totient is φ = 681275424.

The previous prime is 684212159. The next prime is 684212201. The reversal of 684212189 is 981212486.

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 131492089 + 552720100 = 11467^2 + 23510^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-684212189 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 (684212149) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1468034 + ... + 1468499.

It is an arithmetic number, because the mean of its divisors is an integer number (171787239).

Almost surely, 2^684212189 is an apocalyptic number.

It is an amenable number.

684212189 is a deficient number, since it is larger than the sum of its proper divisors (2936767).

684212189 is a wasteful number, since it uses less digits than its factorization.

684212189 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2936766.

The product of its digits is 55296, while the sum is 41.

The square root of 684212189 is about 26157.4499712797. The cubic root of 684212189 is about 881.1779116861.

The spelling of 684212189 in words is "six hundred eighty-four million, two hundred twelve thousand, one hundred eighty-nine".