138438722112781 has 4 divisors (see below), whose sum is σ = 138438755792064. Its totient is φ = 138438688433500.

The previous prime is 138438722112763. The next prime is 138438722112841. The reversal of 138438722112781 is 187211227834831.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-138438722112781 is a prime.

It is a super-2 number, since 2×138438722112781² (a number of 29 digits) contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (138438722113781) 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, 9650965 + ... + 19235866.

It is an arithmetic number, because the mean of its divisors is an integer number (34609688948016).

Almost surely, 2^{138438722112781} is an apocalyptic number.

It is an amenable number.

138438722112781 is a deficient number, since it is larger than the sum of its proper divisors (33679283).

138438722112781 is an equidigital number, since it uses as much as digits as its factorization.

138438722112781 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 33679282.

The product of its digits is 7225344, while the sum is 58.

The spelling of 138438722112781 in words is "one hundred thirty-eight trillion, four hundred thirty-eight billion, seven hundred twenty-two million, one hundred twelve thousand, seven hundred eighty-one".