138547987 has 4 divisors (see below), whose sum is σ = 139842936. Its totient is φ = 137253040.

The previous prime is 138547973. The next prime is 138548023. The reversal of 138547987 is 789745831.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 789745831 = 7 ⋅112820833.

It is a cyclic number.

It is not a de Polignac number, because 138547987 - 2⁷ = 138547859 is a prime.

It is a super-3 number, since 3×138547987³ (a number of 25 digits) contains 333 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (138547957) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 647314 + ... + 647527.

It is an arithmetic number, because the mean of its divisors is an integer number (34960734).

Almost surely, 2^138547987 is an apocalyptic number.

138547987 is a deficient number, since it is larger than the sum of its proper divisors (1294949).

138547987 is a wasteful number, since it uses less digits than its factorization.

138547987 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1294948.

The product of its digits is 1693440, while the sum is 52.

The square root of 138547987 is about 11770.6408916422. The cubic root of 138547987 is about 517.4480326199.

The spelling of 138547987 in words is "one hundred thirty-eight million, five hundred forty-seven thousand, nine hundred eighty-seven".