138081613 has 4 divisors (see below), whose sum is σ = 140345308. Its totient is φ = 135817920.

The previous prime is 138081583. The next prime is 138081641. The reversal of 138081613 is 316180831.

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 75307684 + 62773929 = 8678^2 + 7923^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-138081613 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (138081313) 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, 1131756 + ... + 1131877.

It is an arithmetic number, because the mean of its divisors is an integer number (35086327).

Almost surely, 2^138081613 is an apocalyptic number.

It is an amenable number.

138081613 is a deficient number, since it is larger than the sum of its proper divisors (2263695).

138081613 is an equidigital number, since it uses as much as digits as its factorization.

138081613 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2263694.

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

The square root of 138081613 is about 11750.8132910025. The cubic root of 138081613 is about 516.8667765034.

The spelling of 138081613 in words is "one hundred thirty-eight million, eighty-one thousand, six hundred thirteen".