678204349 has 2 divisors, whose sum is σ = 678204350. Its totient is φ = 678204348.

The previous prime is 678204347. The next prime is 678204367. The reversal of 678204349 is 943402876.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 654438724 + 23765625 = 25582^2 + 4875^2 .

It is a cyclic number.

It is not a de Polignac number, because 678204349 - 2¹ = 678204347 is a prime.

It is a super-2 number, since 2×678204349² = 919922278005027602, which contains 22 as substring.

Together with 678204347, it forms a pair of twin primes.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (678204347) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 339102174 + 339102175.

It is an arithmetic number, because the mean of its divisors is an integer number (339102175).

Almost surely, 2^678204349 is an apocalyptic number.

It is an amenable number.

678204349 is a deficient number, since it is larger than the sum of its proper divisors (1).

678204349 is an equidigital number, since it uses as much as digits as its factorization.

678204349 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 290304, while the sum is 43.

The square root of 678204349 is about 26042.3568249880. The cubic root of 678204349 is about 878.5912156760.

The spelling of 678204349 in words is "six hundred seventy-eight million, two hundred four thousand, three hundred forty-nine".