139221 has 12 divisors (see below), whose sum is σ = 208000. Its totient is φ = 89640.

The previous prime is 139201. The next prime is 139241. The reversal of 139221 is 122931.

It is a happy number.

It is an interprime number because it is at equal distance from previous prime (139201) and next prime (139241).

It is not a de Polignac number, because 139221 - 2¹⁰ = 138197 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 139194 and 139203.

It is a congruent number.

It is an inconsummate number, since it does not exist a number n which divided by its sum of digits gives 139221.

It is not an unprimeable number, because it can be changed into a prime (139201) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 30 + ... + 528.

2¹³⁹²²¹ is an apocalyptic number.

It is an amenable number.

139221 is a deficient number, since it is larger than the sum of its proper divisors (68779).

139221 is a wasteful number, since it uses less digits than its factorization.

139221 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 536 (or 533 counting only the distinct ones).

The product of its digits is 108, while the sum is 18.

The square root of 139221 is about 373.1233040162. The cubic root of 139221 is about 51.8284534326.

Subtracting from 139221 its reverse (122931), we obtain a triangular number (16290 = T₁₈₀).

The spelling of 139221 in words is "one hundred thirty-nine thousand, two hundred twenty-one".