138679649 has 2 divisors, whose sum is σ = 138679650. Its totient is φ = 138679648.

The previous prime is 138679621. The next prime is 138679669. The reversal of 138679649 is 946976831.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 118113424 + 20566225 = 10868^2 + 4535^2 .

It is a cyclic number.

It is not a de Polignac number, because 138679649 - 2²⁴ = 121902433 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 138679649.

It is not a weakly prime, because it can be changed into another prime (138679669) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 69339824 + 69339825.

It is an arithmetic number, because the mean of its divisors is an integer number (69339825).

Almost surely, 2^138679649 is an apocalyptic number.

It is an amenable number.

138679649 is a deficient number, since it is larger than the sum of its proper divisors (1).

138679649 is an equidigital number, since it uses as much as digits as its factorization.

138679649 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 1959552, while the sum is 53.

The square root of 138679649 is about 11776.2323771230. The cubic root of 138679649 is about 517.6118908253.

The spelling of 138679649 in words is "one hundred thirty-eight million, six hundred seventy-nine thousand, six hundred forty-nine".