121210221 has 16 divisors (see below), whose sum is σ = 186677568. Its totient is φ = 69139200.

The previous prime is 121210213. The next prime is 121210231. The reversal of 121210221 is 122012121.

It is not a de Polignac number, because 121210221 - 2³ = 121210213 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 121210197 and 121210206.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (121210231) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 107470 + ... + 108591.

It is an arithmetic number, because the mean of its divisors is an integer number (11667348).

Almost surely, 2^121210221 is an apocalyptic number.

121210221 is a gapful number since it is divisible by the number (11) formed by its first and last digit.

It is an amenable number.

121210221 is a deficient number, since it is larger than the sum of its proper divisors (65467347).

121210221 is a wasteful number, since it uses less digits than its factorization.

121210221 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 216092.

The product of its (nonzero) digits is 16, while the sum is 12.

The square root of 121210221 is about 11009.5513532569. The cubic root of 121210221 is about 494.8950170178.

Adding to 121210221 its reverse (122012121), we get a palindrome (243222342).

The spelling of 121210221 in words is "one hundred twenty-one million, two hundred ten thousand, two hundred twenty-one".