138221444 has 12 divisors (see below), whose sum is σ = 252404544. Its totient is φ = 66105864.

The previous prime is 138221437. The next prime is 138221459. The reversal of 138221444 is 444122831.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 751112 + ... + 751295.

It is an arithmetic number, because the mean of its divisors is an integer number (21033712).

Almost surely, 2^138221444 is an apocalyptic number.

It is an amenable number.

138221444 is a deficient number, since it is larger than the sum of its proper divisors (114183100).

138221444 is a wasteful number, since it uses less digits than its factorization.

138221444 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1502434 (or 1502432 counting only the distinct ones).

The product of its digits is 6144, while the sum is 29.

The square root of 138221444 is about 11756.7616289521. The cubic root of 138221444 is about 517.0411893351.

The spelling of 138221444 in words is "one hundred thirty-eight million, two hundred twenty-one thousand, four hundred forty-four".