138787993 has 16 divisors (see below), whose sum is σ = 145740672. Its totient is φ = 132048000.

The previous prime is 138787991. The next prime is 138788029. The reversal of 138787993 is 399787831.

It is a cyclic number.

It is not a de Polignac number, because 138787993 - 2¹ = 138787991 is a prime.

It is a Duffinian number.

Its product of digits (2286144) is a multiple of the sum of its prime divisors (576).

It is not an unprimeable number, because it can be changed into a prime (138787991) 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 15 ways as a sum of consecutive naturals, for example, 527580 + ... + 527842.

It is an arithmetic number, because the mean of its divisors is an integer number (9108792).

Almost surely, 2^138787993 is an apocalyptic number.

It is an amenable number.

138787993 is a deficient number, since it is larger than the sum of its proper divisors (6952679).

138787993 is a wasteful number, since it uses less digits than its factorization.

138787993 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 576.

The product of its digits is 2286144, while the sum is 55.

The square root of 138787993 is about 11780.8315920397. The cubic root of 138787993 is about 517.7466511528.

The spelling of 138787993 in words is "one hundred thirty-eight million, seven hundred eighty-seven thousand, nine hundred ninety-three".