138263215 has 4 divisors (see below), whose sum is σ = 165915864. Its totient is φ = 110610568.

The previous prime is 138263207. The next prime is 138263231. The reversal of 138263215 is 512362831.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 512362831 = 127 ⋅4034353.

It is a cyclic number.

It is not a de Polignac number, because 138263215 - 2³ = 138263207 is a prime.

It is a Duffinian number.

It is a congruent number.

It is an unprimeable number.

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, 13826317 + ... + 13826326.

It is an arithmetic number, because the mean of its divisors is an integer number (41478966).

Almost surely, 2^138263215 is an apocalyptic number.

138263215 is a deficient number, since it is larger than the sum of its proper divisors (27652649).

138263215 is an equidigital number, since it uses as much as digits as its factorization.

138263215 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 27652648.

The product of its digits is 8640, while the sum is 31.

The square root of 138263215 is about 11758.5379618386. The cubic root of 138263215 is about 517.0932679698.

The spelling of 138263215 in words is "one hundred thirty-eight million, two hundred sixty-three thousand, two hundred fifteen".