678634181 has 2 divisors, whose sum is σ = 678634182. Its totient is φ = 678634180.

The previous prime is 678634171. The next prime is 678634199. The reversal of 678634181 is 181436876.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 629508100 + 49126081 = 25090^2 + 7009^2 .

It is a cyclic number.

It is not a de Polignac number, because 678634181 - 2¹⁰ = 678633157 is a prime.

It is a super-2 number, since 2×678634181² = 921088703243081522, which contains 22 as substring.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (678634111) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 339317090 + 339317091.

It is an arithmetic number, because the mean of its divisors is an integer number (339317091).

Almost surely, 2^678634181 is an apocalyptic number.

It is an amenable number.

678634181 is a deficient number, since it is larger than the sum of its proper divisors (1).

678634181 is an equidigital number, since it uses as much as digits as its factorization.

678634181 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 193536, while the sum is 44.

The square root of 678634181 is about 26050.6080735172. The cubic root of 678634181 is about 878.7767875058.

The spelling of 678634181 in words is "six hundred seventy-eight million, six hundred thirty-four thousand, one hundred eighty-one".