121001222221 has 6 divisors (see below), whose sum is σ = 133001343566. Its totient is φ = 110001111000.

The previous prime is 121001222179. The next prime is 121001222249. The reversal of 121001222221 is 122222100121.

It is a happy number.

It can be written as a sum of positive squares in only one way, i.e., 105621750025 + 15379472196 = 324995^2 + 124014^2 .

It is not a de Polignac number, because 121001222221 - 2¹¹ = 121001220173 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 121001222195 and 121001222204.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (121001222291) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 500004930 + ... + 500005171.

Almost surely, 2^121001222221 is an apocalyptic number.

121001222221 is a gapful number since it is divisible by the number (11) formed by its first and last digit.

It is an amenable number.

121001222221 is a deficient number, since it is larger than the sum of its proper divisors (12000121345).

121001222221 is a wasteful number, since it uses less digits than its factorization.

121001222221 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1000010123 (or 1000010112 counting only the distinct ones).

The product of its (nonzero) digits is 64, while the sum is 16.

Adding to 121001222221 its reverse (122222100121), we get a palindrome (243223322342).

It can be divided in two parts, 12100 and 1222221, that added together give a palindrome (1234321).

The spelling of 121001222221 in words is "one hundred twenty-one billion, one million, two hundred twenty-two thousand, two hundred twenty-one".