678049249 has 2 divisors, whose sum is σ = 678049250. Its totient is φ = 678049248.

The previous prime is 678049247. The next prime is 678049279. The reversal of 678049249 is 942940876.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 391762849 + 286286400 = 19793^2 + 16920^2 .

It is a cyclic number.

It is not a de Polignac number, because 678049249 - 2¹ = 678049247 is a prime.

Together with 678049247, it forms a pair of twin primes.

It is not a weakly prime, because it can be changed into another prime (678049243) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 339024624 + 339024625.

It is an arithmetic number, because the mean of its divisors is an integer number (339024625).

Almost surely, 2^678049249 is an apocalyptic number.

It is an amenable number.

678049249 is a deficient number, since it is larger than the sum of its proper divisors (1).

678049249 is an equidigital number, since it uses as much as digits as its factorization.

678049249 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 870912, while the sum is 49.

The square root of 678049249 is about 26039.3788136353. The cubic root of 678049249 is about 878.5242349364.

The spelling of 678049249 in words is "six hundred seventy-eight million, forty-nine thousand, two hundred forty-nine".