138766 has 4 divisors (see below), whose sum is σ = 208152. Its totient is φ = 69382.

The previous prime is 138763. The next prime is 138793. The reversal of 138766 is 667831.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 667831 = 19 ⋅35149.

It is a Smith number, since the sum of its digits (31) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (138763) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 34690 + ... + 34693.

It is an arithmetic number, because the mean of its divisors is an integer number (52038).

2¹³⁸⁷⁶⁶ is an apocalyptic number.

138766 is a deficient number, since it is larger than the sum of its proper divisors (69386).

138766 is an equidigital number, since it uses as much as digits as its factorization.

138766 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 69385.

The product of its digits is 6048, while the sum is 31.

The square root of 138766 is about 372.5130870184. The cubic root of 138766 is about 51.7719301516.

The spelling of 138766 in words is "one hundred thirty-eight thousand, seven hundred sixty-six".