138855787 has 4 divisors (see below), whose sum is σ = 158692336. Its totient is φ = 119019240.

The previous prime is 138855757. The next prime is 138855797. The reversal of 138855787 is 787558831.

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 138855787 - 2⁷ = 138855659 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (138855757) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 9918264 + ... + 9918277.

It is an arithmetic number, because the mean of its divisors is an integer number (39673084).

Almost surely, 2^138855787 is an apocalyptic number.

138855787 is a deficient number, since it is larger than the sum of its proper divisors (19836549).

138855787 is an equidigital number, since it uses as much as digits as its factorization.

138855787 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 19836548.

The product of its digits is 1881600, while the sum is 52.

The square root of 138855787 is about 11783.7085418810. The cubic root of 138855787 is about 517.8309389506.

It can be divided in two parts, 1388 and 55787, that added together give a palindrome (57175).

The spelling of 138855787 in words is "one hundred thirty-eight million, eight hundred fifty-five thousand, seven hundred eighty-seven".