138986 has 4 divisors (see below), whose sum is σ = 208482. Its totient is φ = 69492.

The previous prime is 138977. The next prime is 139021. The reversal of 138986 is 689831.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in only one way, i.e., 78961 + 60025 = 281^2 + 245^2 .

It is an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 34745 + ... + 34748.

2¹³⁸⁹⁸⁶ is an apocalyptic number.

138986 is a deficient number, since it is larger than the sum of its proper divisors (69496).

138986 is an equidigital number, since it uses as much as digits as its factorization.

138986 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 69495.

The product of its digits is 10368, while the sum is 35.

The square root of 138986 is about 372.8082617110. The cubic root of 138986 is about 51.7992754926.

The spelling of 138986 in words is "one hundred thirty-eight thousand, nine hundred eighty-six".