138128222 has 4 divisors (see below), whose sum is σ = 207192336. Its totient is φ = 69064110.

The previous prime is 138128209. The next prime is 138128227. The reversal of 138128222 is 222821831.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 222821831 = 31 ⋅7187801.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (138128227) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 34532054 + ... + 34532057.

It is an arithmetic number, because the mean of its divisors is an integer number (51798084).

Almost surely, 2^138128222 is an apocalyptic number.

138128222 is a deficient number, since it is larger than the sum of its proper divisors (69064114).

138128222 is an equidigital number, since it uses as much as digits as its factorization.

138128222 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 69064113.

The product of its digits is 3072, while the sum is 29.

The square root of 138128222 is about 11752.7963481037. The cubic root of 138128222 is about 516.9249255284.

The spelling of 138128222 in words is "one hundred thirty-eight million, one hundred twenty-eight thousand, two hundred twenty-two".