678206149 has 2 divisors, whose sum is σ = 678206150. Its totient is φ = 678206148.

The previous prime is 678206071. The next prime is 678206201. The reversal of 678206149 is 941602876.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 526473025 + 151733124 = 22945^2 + 12318^2 .

It is a cyclic number.

It is not a de Polignac number, because 678206149 - 2⁹ = 678205637 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (678206549) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 339103074 + 339103075.

It is an arithmetic number, because the mean of its divisors is an integer number (339103075).

Almost surely, 2^678206149 is an apocalyptic number.

It is an amenable number.

678206149 is a deficient number, since it is larger than the sum of its proper divisors (1).

678206149 is an equidigital number, since it uses as much as digits as its factorization.

678206149 is an evil number, because the sum of its binary digits is even.

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

The square root of 678206149 is about 26042.3913840492. The cubic root of 678206149 is about 878.5919929554.

The spelling of 678206149 in words is "six hundred seventy-eight million, two hundred six thousand, one hundred forty-nine".