138016381 has 4 divisors (see below), whose sum is σ = 138067200. Its totient is φ = 137965564.

The previous prime is 138016367. The next prime is 138016391. The reversal of 138016381 is 183610831.

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, and also an emirpimes, since its reverse is a distinct semiprime: 183610831 = 1637 ⋅112163.

It is a cyclic number.

It is not a de Polignac number, because 138016381 - 2⁵ = 138016349 is a prime.

It is a super-2 number, since 2×138016381² = 38097042848674322, which 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 (138016321) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 21091 + ... + 26848.

It is an arithmetic number, because the mean of its divisors is an integer number (34516800).

Almost surely, 2^138016381 is an apocalyptic number.

It is an amenable number.

138016381 is a deficient number, since it is larger than the sum of its proper divisors (50819).

138016381 is an equidigital number, since it uses as much as digits as its factorization.

138016381 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 50818.

The product of its (nonzero) digits is 3456, while the sum is 31.

The square root of 138016381 is about 11748.0373254429. The cubic root of 138016381 is about 516.7853715922.

The spelling of 138016381 in words is "one hundred thirty-eight million, sixteen thousand, three hundred eighty-one".