138261815 has 8 divisors (see below), whose sum is σ = 167913648. Its totient is φ = 109276480.

The previous prime is 138261797. The next prime is 138261847. The reversal of 138261815 is 518162831.

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 138261815 - 2⁶ = 138261751 is a prime.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 166166 + ... + 166995.

It is an arithmetic number, because the mean of its divisors is an integer number (20989206).

Almost surely, 2^138261815 is an apocalyptic number.

138261815 is a deficient number, since it is larger than the sum of its proper divisors (29651833).

138261815 is an equidigital number, since it uses as much as digits as its factorization.

138261815 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 333249.

The product of its digits is 11520, while the sum is 35.

The square root of 138261815 is about 11758.4784304773. The cubic root of 138261815 is about 517.0915226683.

The spelling of 138261815 in words is "one hundred thirty-eight million, two hundred sixty-one thousand, eight hundred fifteen".