138239743 has 4 divisors (see below), whose sum is σ = 138843640. Its totient is φ = 137635848.

The previous prime is 138239719. The next prime is 138239747. The reversal of 138239743 is 347932831.

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

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-138239743 is a prime.

It is a super-2 number, since 2×138239743² = 38220453089412098, which contains 22 as substring.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 138239696 and 138239705.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (138239747) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 301605 + ... + 302062.

It is an arithmetic number, because the mean of its divisors is an integer number (34710910).

Almost surely, 2^138239743 is an apocalyptic number.

138239743 is a deficient number, since it is larger than the sum of its proper divisors (603897).

138239743 is an equidigital number, since it uses as much as digits as its factorization.

138239743 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 603896.

The product of its digits is 108864, while the sum is 40.

The square root of 138239743 is about 11757.5398362072. The cubic root of 138239743 is about 517.0640051852.

The spelling of 138239743 in words is "one hundred thirty-eight million, two hundred thirty-nine thousand, seven hundred forty-three".