138738866 has 16 divisors (see below), whose sum is σ = 238413120. Its totient is φ = 59315760.

The previous prime is 138738851. The next prime is 138738881. The reversal of 138738866 is 668837831.

138738866 is digitally balanced in base 3, because in such base it contains all the possibile digits an equal number of times.

It is an interprime number because it is at equal distance from previous prime (138738851) and next prime (138738881).

It is an unprimeable number.

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 7 ways as a sum of consecutive naturals, for example, 5876 + ... + 17663.

It is an arithmetic number, because the mean of its divisors is an integer number (14900820).

Almost surely, 2^138738866 is an apocalyptic number.

138738866 is a deficient number, since it is larger than the sum of its proper divisors (99674254).

138738866 is a wasteful number, since it uses less digits than its factorization.

138738866 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 23969.

The product of its digits is 1161216, while the sum is 50.

The square root of 138738866 is about 11778.7463679290. The cubic root of 138738866 is about 517.6855547498.

The spelling of 138738866 in words is "one hundred thirty-eight million, seven hundred thirty-eight thousand, eight hundred sixty-six".