138987 has 6 divisors (see below), whose sum is σ = 200772. Its totient is φ = 92652.

The previous prime is 138977. The next prime is 139021. The reversal of 138987 is 789831.

It is not a de Polignac number, because 138987 - 2⁶ = 138923 is a prime.

It is an Ulam number.

It is an inconsummate number, since it does not exist a number n which divided by its sum of digits gives 138987.

It is not an unprimeable number, because it can be changed into a prime (138917) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 7713 + ... + 7730.

It is an arithmetic number, because the mean of its divisors is an integer number (33462).

2¹³⁸⁹⁸⁷ is an apocalyptic number.

138987 is a deficient number, since it is larger than the sum of its proper divisors (61785).

138987 is a wasteful number, since it uses less digits than its factorization.

138987 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 15449 (or 15446 counting only the distinct ones).

The product of its digits is 12096, while the sum is 36.

The square root of 138987 is about 372.8096028806. The cubic root of 138987 is about 51.7993997237.

The spelling of 138987 in words is "one hundred thirty-eight thousand, nine hundred eighty-seven".