138818771 has 16 divisors (see below), whose sum is σ = 173202624. Its totient is φ = 108324864.

The previous prime is 138818767. The next prime is 138818789. The reversal of 138818771 is 177818831.

It is a happy number.

It is a cyclic number.

It is not a de Polignac number, because 138818771 - 2² = 138818767 is a prime.

It is not an unprimeable number, because it can be changed into a prime (138818711) 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, 3806 + ... + 17091.

It is an arithmetic number, because the mean of its divisors is an integer number (10825164).

Almost surely, 2^138818771 is an apocalyptic number.

138818771 is a deficient number, since it is larger than the sum of its proper divisors (34383853).

138818771 is a wasteful number, since it uses less digits than its factorization.

138818771 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 20990.

The product of its digits is 75264, while the sum is 44.

The square root of 138818771 is about 11782.1377941357. The cubic root of 138818771 is about 517.7849206224.

The spelling of 138818771 in words is "one hundred thirty-eight million, eight hundred eighteen thousand, seven hundred seventy-one".