138085481 has 4 divisors (see below), whose sum is σ = 138477012. Its totient is φ = 137693952.

The previous prime is 138085469. The next prime is 138085487. The reversal of 138085481 is 184580831.

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

It can be written as a sum of positive squares in 2 ways, for example, as 28987456 + 109098025 = 5384^2 + 10445^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-138085481 is a prime.

It is a super-2 number, since 2×138085481² = 38135200126002722, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (138085487) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 195236 + ... + 195941.

It is an arithmetic number, because the mean of its divisors is an integer number (34619253).

Almost surely, 2^138085481 is an apocalyptic number.

It is an amenable number.

138085481 is a deficient number, since it is larger than the sum of its proper divisors (391531).

138085481 is an equidigital number, since it uses as much as digits as its factorization.

138085481 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 391530.

The product of its (nonzero) digits is 30720, while the sum is 38.

The square root of 138085481 is about 11750.9778742026. The cubic root of 138085481 is about 516.8716026879.

The spelling of 138085481 in words is "one hundred thirty-eight million, eighty-five thousand, four hundred eighty-one".