684947149 has 2 divisors, whose sum is σ = 684947150. Its totient is φ = 684947148.

The previous prime is 684947099. The next prime is 684947161. The reversal of 684947149 is 941749486.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 588062500 + 96884649 = 24250^2 + 9843^2 .

It is a cyclic number.

It is not a de Polignac number, because 684947149 - 2¹⁹ = 684422861 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 684947096 and 684947105.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (684947849) 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 as a sum of consecutive naturals, namely, 342473574 + 342473575.

It is an arithmetic number, because the mean of its divisors is an integer number (342473575).

Almost surely, 2^684947149 is an apocalyptic number.

It is an amenable number.

684947149 is a deficient number, since it is larger than the sum of its proper divisors (1).

684947149 is an equidigital number, since it uses as much as digits as its factorization.

684947149 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 1741824, while the sum is 52.

The square root of 684947149 is about 26171.4949706737. The cubic root of 684947149 is about 881.4933103194.

The spelling of 684947149 in words is "six hundred eighty-four million, nine hundred forty-seven thousand, one hundred forty-nine".