138888751 has 4 divisors (see below), whose sum is σ = 138915000. Its totient is φ = 138862504.

The previous prime is 138888707. The next prime is 138888767. The reversal of 138888751 is 157888831.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 157888831 = 4129 ⋅38239.

It is a cyclic number.

It is not a de Polignac number, because 138888751 - 2¹¹ = 138886703 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 138888695 and 138888704.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (138888791) 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, 2101 + ... + 16798.

It is an arithmetic number, because the mean of its divisors is an integer number (34728750).

Almost surely, 2^138888751 is an apocalyptic number.

138888751 is a deficient number, since it is larger than the sum of its proper divisors (26249).

138888751 is an equidigital number, since it uses as much as digits as its factorization.

138888751 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 26248.

The product of its digits is 430080, while the sum is 49.

The square root of 138888751 is about 11785.1071696442. The cubic root of 138888751 is about 517.8719129445.

The spelling of 138888751 in words is "one hundred thirty-eight million, eight hundred eighty-eight thousand, seven hundred fifty-one".