121222221 has 4 divisors (see below), whose sum is σ = 161629632. Its totient is φ = 80814812.

The previous prime is 121222193. The next prime is 121222237. The reversal of 121222221 is 122222121.

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 not a de Polignac number, because 121222221 - 2¹¹ = 121220173 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 121222221.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (121222421) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 20203701 + ... + 20203706.

It is an arithmetic number, because the mean of its divisors is an integer number (40407408).

Almost surely, 2^121222221 is an apocalyptic number.

It is an amenable number.

121222221 is a deficient number, since it is larger than the sum of its proper divisors (40407411).

121222221 is an equidigital number, since it uses as much as digits as its factorization.

121222221 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 40407410.

The product of its digits is 64, while the sum is 15.

The square root of 121222221 is about 11010.0963211046. The cubic root of 121222221 is about 494.9113482704.

Adding to 121222221 its reverse (122222121), we get a palindrome (243444342).

It can be divided in two parts, 12122 and 2221, that multiplied together give a palindrome (26922962).

The spelling of 121222221 in words is "one hundred twenty-one million, two hundred twenty-two thousand, two hundred twenty-one".