678138613 has 2 divisors, whose sum is σ = 678138614. Its totient is φ = 678138612.

The previous prime is 678138583. The next prime is 678138673. The reversal of 678138613 is 316831876.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 572501329 + 105637284 = 23927^2 + 10278^2 .

It is a cyclic number.

It is not a de Polignac number, because 678138613 - 2¹³ = 678130421 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 678138613.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (678138673) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 339069306 + 339069307.

It is an arithmetic number, because the mean of its divisors is an integer number (339069307).

Almost surely, 2^678138613 is an apocalyptic number.

It is an amenable number.

678138613 is a deficient number, since it is larger than the sum of its proper divisors (1).

678138613 is an equidigital number, since it uses as much as digits as its factorization.

678138613 is an evil number, because the sum of its binary digits is even.

The product of its digits is 145152, while the sum is 43.

The square root of 678138613 is about 26041.0946966521. The cubic root of 678138613 is about 878.5628284904.

The spelling of 678138613 in words is "six hundred seventy-eight million, one hundred thirty-eight thousand, six hundred thirteen".