684947161 has 2 divisors, whose sum is σ = 684947162. Its totient is φ = 684947160.

The previous prime is 684947149. The next prime is 684947177. The reversal of 684947161 is 161749486.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 608559561 + 76387600 = 24669^2 + 8740^2 .

It is a cyclic number.

It is not a de Polignac number, because 684947161 - 2⁹ = 684946649 is a prime.

It is a super-2 number, since 2×684947161² = 938305226723919842, which contains 22 as substring.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (684945161) 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, 342473580 + 342473581.

It is an arithmetic number, because the mean of its divisors is an integer number (342473581).

Almost surely, 2^684947161 is an apocalyptic number.

It is an amenable number.

684947161 is a deficient number, since it is larger than the sum of its proper divisors (1).

684947161 is an equidigital number, since it uses as much as digits as its factorization.

684947161 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 290304, while the sum is 46.

The square root of 684947161 is about 26171.4951999308. The cubic root of 684947161 is about 881.4933154672.

The spelling of 684947161 in words is "six hundred eighty-four million, nine hundred forty-seven thousand, one hundred sixty-one".