138787639 has 4 divisors (see below), whose sum is σ = 139240024. Its totient is φ = 138335256.

The previous prime is 138787637. The next prime is 138787657. The reversal of 138787639 is 936787831.

It is a happy number.

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

It is a cyclic number.

It is not a de Polignac number, because 138787639 - 2¹ = 138787637 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 (138787633) 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, 225732 + ... + 226345.

It is an arithmetic number, because the mean of its divisors is an integer number (34810006).

Almost surely, 2^138787639 is an apocalyptic number.

138787639 is a deficient number, since it is larger than the sum of its proper divisors (452385).

138787639 is an equidigital number, since it uses as much as digits as its factorization.

138787639 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 452384.

The product of its digits is 1524096, while the sum is 52.

The square root of 138787639 is about 11780.8165676238. The cubic root of 138787639 is about 517.7462109551.

The spelling of 138787639 in words is "one hundred thirty-eight million, seven hundred eighty-seven thousand, six hundred thirty-nine".