680909189 has 2 divisors, whose sum is σ = 680909190. Its totient is φ = 680909188.

The previous prime is 680909167. The next prime is 680909221. The reversal of 680909189 is 981909086.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 429940225 + 250968964 = 20735^2 + 15842^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-680909189 is a prime.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (680909129) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 340454594 + 340454595.

It is an arithmetic number, because the mean of its divisors is an integer number (340454595).

Almost surely, 2^680909189 is an apocalyptic number.

It is an amenable number.

680909189 is a deficient number, since it is larger than the sum of its proper divisors (1).

680909189 is an equidigital number, since it uses as much as digits as its factorization.

680909189 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 279936, while the sum is 50.

The square root of 680909189 is about 26094.2367008502. The cubic root of 680909189 is about 879.7576764771.

The spelling of 680909189 in words is "six hundred eighty million, nine hundred nine thousand, one hundred eighty-nine".