138315505 has 4 divisors (see below), whose sum is σ = 165978612. Its totient is φ = 110652400.

The previous prime is 138315493. The next prime is 138315517. The reversal of 138315505 is 505513831.

138315505 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 505513831 = 73 ⋅6924847.

It is an interprime number because it is at equal distance from previous prime (138315493) and next prime (138315517).

It can be written as a sum of positive squares in 2 ways, for example, as 18215824 + 120099681 = 4268^2 + 10959^2 .

It is not a de Polignac number, because 138315505 - 2⁹ = 138314993 is a prime.

It is a Smith number, since the sum of its digits (31) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

It is a Duffinian number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 13831546 + ... + 13831555.

It is an arithmetic number, because the mean of its divisors is an integer number (41494653).

Almost surely, 2^138315505 is an apocalyptic number.

It is an amenable number.

138315505 is a deficient number, since it is larger than the sum of its proper divisors (27663107).

138315505 is an equidigital number, since it uses as much as digits as its factorization.

138315505 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 27663106.

The product of its (nonzero) digits is 9000, while the sum is 31.

The square root of 138315505 is about 11760.7612423686. The cubic root of 138315505 is about 517.1584465475.

The spelling of 138315505 in words is "one hundred thirty-eight million, three hundred fifteen thousand, five hundred five".