684390149 has 2 divisors, whose sum is σ = 684390150. Its totient is φ = 684390148.

The previous prime is 684390143. The next prime is 684390151. The reversal of 684390149 is 941093486.

684390149 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 537544225 + 146845924 = 23185^2 + 12118^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-684390149 is a prime.

It is a super-3 number, since 3×684390149³ (a number of 27 digits) contains 333 as substring.

Together with 684390151, it forms a pair of twin primes.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (684390143) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 342195074 + 342195075.

It is an arithmetic number, because the mean of its divisors is an integer number (342195075).

Almost surely, 2^684390149 is an apocalyptic number.

It is an amenable number.

684390149 is a deficient number, since it is larger than the sum of its proper divisors (1).

684390149 is an equidigital number, since it uses as much as digits as its factorization.

684390149 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 186624, while the sum is 44.

The square root of 684390149 is about 26160.8514578559. The cubic root of 684390149 is about 881.2543016473.

The spelling of 684390149 in words is "six hundred eighty-four million, three hundred ninety thousand, one hundred forty-nine".