678338917 has 2 divisors, whose sum is σ = 678338918. Its totient is φ = 678338916.

The previous prime is 678338861. The next prime is 678338933. The reversal of 678338917 is 719833876.

It is a happy number.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 674648676 + 3690241 = 25974^2 + 1921^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-678338917 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (678338957) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 339169458 + 339169459.

It is an arithmetic number, because the mean of its divisors is an integer number (339169459).

Almost surely, 2^678338917 is an apocalyptic number.

It is an amenable number.

678338917 is a deficient number, since it is larger than the sum of its proper divisors (1).

678338917 is an equidigital number, since it uses as much as digits as its factorization.

678338917 is an evil number, because the sum of its binary digits is even.

The product of its digits is 1524096, while the sum is 52.

The square root of 678338917 is about 26044.9403339689. The cubic root of 678338917 is about 878.6493212918.

The spelling of 678338917 in words is "six hundred seventy-eight million, three hundred thirty-eight thousand, nine hundred seventeen".