139138221 has 12 divisors (see below), whose sum is σ = 186747392. Its totient is φ = 92147928.

The previous prime is 139138193. The next prime is 139138231. The reversal of 139138221 is 122831931.

It is not a de Polignac number, because 139138221 - 2⁶ = 139138157 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (139138231) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 82836 + ... + 84498.

Almost surely, 2^139138221 is an apocalyptic number.

It is an amenable number.

139138221 is a deficient number, since it is larger than the sum of its proper divisors (47609171).

139138221 is an equidigital number, since it uses as much as digits as its factorization.

139138221 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2000 (or 1833 counting only the distinct ones).

The product of its digits is 2592, while the sum is 30.

The square root of 139138221 is about 11795.6865421221. The cubic root of 139138221 is about 518.1817922074.

The spelling of 139138221 in words is "one hundred thirty-nine million, one hundred thirty-eight thousand, two hundred twenty-one".