138818155 has 32 divisors (see below), whose sum is σ = 198696960. Its totient is φ = 91100160.

The previous prime is 138818153. The next prime is 138818201. The reversal of 138818155 is 551818831.

It is not a de Polignac number, because 138818155 - 2¹ = 138818153 is a prime.

It is not an unprimeable number, because it can be changed into a prime (138818153) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 104586 + ... + 105904.

It is an arithmetic number, because the mean of its divisors is an integer number (6209280).

Almost surely, 2^138818155 is an apocalyptic number.

138818155 is a deficient number, since it is larger than the sum of its proper divisors (59878805).

138818155 is a wasteful number, since it uses less digits than its factorization.

138818155 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1459.

The product of its digits is 38400, while the sum is 40.

The square root of 138818155 is about 11782.1116528405. Note that the first 3 decimals coincide. The cubic root of 138818155 is about 517.7841547414.

The spelling of 138818155 in words is "one hundred thirty-eight million, eight hundred eighteen thousand, one hundred fifty-five".