138197815 has 16 divisors (see below), whose sum is σ = 189729792. Its totient is φ = 94663584.

The previous prime is 138197809. The next prime is 138197819. The reversal of 138197815 is 518791831.

It is a cyclic number.

It is not a de Polignac number, because 138197815 - 2¹⁷ = 138066743 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (138197819) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 48562 + ... + 51328.

It is an arithmetic number, because the mean of its divisors is an integer number (11858112).

Almost surely, 2^138197815 is an apocalyptic number.

138197815 is a deficient number, since it is larger than the sum of its proper divisors (51531977).

138197815 is a wasteful number, since it uses less digits than its factorization.

138197815 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4206.

The product of its digits is 60480, while the sum is 43.

The square root of 138197815 is about 11755.7566749231. The cubic root of 138197815 is about 517.0117248706.

The spelling of 138197815 in words is "one hundred thirty-eight million, one hundred ninety-seven thousand, eight hundred fifteen".