121838221 has 4 divisors (see below), whose sum is σ = 124671712. Its totient is φ = 119004732.

The previous prime is 121838209. The next prime is 121838239. The reversal of 121838221 is 122838121.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-121838221 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 121838221.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (121838261) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1416681 + ... + 1416766.

It is an arithmetic number, because the mean of its divisors is an integer number (31167928).

Almost surely, 2^121838221 is an apocalyptic number.

It is an amenable number.

121838221 is a deficient number, since it is larger than the sum of its proper divisors (2833491).

121838221 is an equidigital number, since it uses as much as digits as its factorization.

121838221 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2833490.

The product of its digits is 1536, while the sum is 28.

The square root of 121838221 is about 11038.0351965375. The cubic root of 121838221 is about 495.7482422601.

The spelling of 121838221 in words is "one hundred twenty-one million, eight hundred thirty-eight thousand, two hundred twenty-one".