678338861 has 2 divisors, whose sum is σ = 678338862. Its totient is φ = 678338860.

The previous prime is 678338833. The next prime is 678338917. The reversal of 678338861 is 168833876.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 609349225 + 68989636 = 24685^2 + 8306^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-678338861 is a prime.

It is a super-2 number, since 2×678338861² = 920287220685554642, 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 (678338761) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 339169430 + 339169431.

It is an arithmetic number, because the mean of its divisors is an integer number (339169431).

Almost surely, 2^678338861 is an apocalyptic number.

It is an amenable number.

678338861 is a deficient number, since it is larger than the sum of its proper divisors (1).

678338861 is an equidigital number, since it uses as much as digits as its factorization.

678338861 is an evil number, because the sum of its binary digits is even.

The product of its digits is 1161216, while the sum is 50.

The square root of 678338861 is about 26044.9392589040. The cubic root of 678338861 is about 878.6492971129.

The spelling of 678338861 in words is "six hundred seventy-eight million, three hundred thirty-eight thousand, eight hundred sixty-one".