138987511 has 8 divisors (see below), whose sum is σ = 149775584. Its totient is φ = 128213280.

The previous prime is 138987509. The next prime is 138987521. The reversal of 138987511 is 115789831.

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 138987511 - 2¹ = 138987509 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (138987521) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 28150 + ... + 32716.

It is an arithmetic number, because the mean of its divisors is an integer number (18721948).

Almost surely, 2^138987511 is an apocalyptic number.

138987511 is a deficient number, since it is larger than the sum of its proper divisors (10788073).

138987511 is a wasteful number, since it uses less digits than its factorization.

138987511 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 6921.

The product of its digits is 60480, while the sum is 43.

The square root of 138987511 is about 11789.2964590768. The cubic root of 138987511 is about 517.9946320558.

The spelling of 138987511 in words is "one hundred thirty-eight million, nine hundred eighty-seven thousand, five hundred eleven".