678138657 has 16 divisors (see below), whose sum is σ = 1052853120. Its totient is φ = 380195712.

The previous prime is 678138613. The next prime is 678138673. The reversal of 678138657 is 756831876.

It is not a de Polignac number, because 678138657 - 2²² = 673944353 is a prime.

It is not an unprimeable number, because it can be changed into a prime (678138677) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 303532 + ... + 305757.

It is an arithmetic number, because the mean of its divisors is an integer number (65803320).

Almost surely, 2^678138657 is an apocalyptic number.

It is an amenable number.

678138657 is a deficient number, since it is larger than the sum of its proper divisors (374714463).

678138657 is a wasteful number, since it uses less digits than its factorization.

678138657 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 609352.

The product of its digits is 1693440, while the sum is 51.

The square root of 678138657 is about 26041.0955414706. The cubic root of 678138657 is about 878.5628474918.

The spelling of 678138657 in words is "six hundred seventy-eight million, one hundred thirty-eight thousand, six hundred fifty-seven".