678040109 has 2 divisors, whose sum is σ = 678040110. Its totient is φ = 678040108.

The previous prime is 678040079. The next prime is 678040123. The reversal of 678040109 is 901040876.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 662908009 + 15132100 = 25747^2 + 3890^2 .

It is a cyclic number.

It is not a de Polignac number, because 678040109 - 2⁸ = 678039853 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (678040309) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 339020054 + 339020055.

It is an arithmetic number, because the mean of its divisors is an integer number (339020055).

Almost surely, 2^678040109 is an apocalyptic number.

It is an amenable number.

678040109 is a deficient number, since it is larger than the sum of its proper divisors (1).

678040109 is an equidigital number, since it uses as much as digits as its factorization.

678040109 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 12096, while the sum is 35.

The square root of 678040109 is about 26039.2033096253. The cubic root of 678040109 is about 878.5202874613.

The spelling of 678040109 in words is "six hundred seventy-eight million, forty thousand, one hundred nine".