138866 has 24 divisors (see below), whose sum is σ = 263340. Its totient is φ = 54432.

The previous prime is 138863. The next prime is 138869. The reversal of 138866 is 668831.

138866 is digitally balanced in base 2, 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 (138863) and next prime (138869).

It can be written as a sum of positive squares in 2 ways, for example, as 137641 + 1225 = 371^2 + 35^2 .

It is an inconsummate number, since it does not exist a number n which divided by its sum of digits gives 138866.

It is not an unprimeable number, because it can be changed into a prime (138863) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 1220 + ... + 1328.

2¹³⁸⁸⁶⁶ is an apocalyptic number.

138866 is a deficient number, since it is larger than the sum of its proper divisors (124474).

138866 is a wasteful number, since it uses less digits than its factorization.

138866 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 138 (or 131 counting only the distinct ones).

The product of its digits is 6912, while the sum is 32.

The square root of 138866 is about 372.6472863178. The cubic root of 138866 is about 51.7843634323.

The spelling of 138866 in words is "one hundred thirty-eight thousand, eight hundred sixty-six".