121212112222221 has 16 divisors (see below), whose sum is σ = 165989161102848. Its totient is φ = 78621700852800.

The previous prime is 121212112222211. The next prime is 121212112222297. The reversal of 121212112222221 is 122222211212121.

It is not a de Polignac number, because 121212112222221 - 2⁷ = 121212112222093 is a prime.

It is a super-2 number, since 2×121212112222221² (a number of 29 digits) contains 22 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 121212112222191 and 121212112222200.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (121212112222211) 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, 12772125 + ... + 20138306.

It is an arithmetic number, because the mean of its divisors is an integer number (10374322568928).

Almost surely, 2^{121212112222221} is an apocalyptic number.

It is an amenable number.

121212112222221 is a deficient number, since it is larger than the sum of its proper divisors (44777048880627).

121212112222221 is a wasteful number, since it uses less digits than its factorization.

121212112222221 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 32943652.

The product of its digits is 512, while the sum is 24.

Adding to 121212112222221 its reverse (122222211212121), we get a palindrome (243434323434342).

The spelling of 121212112222221 in words is "one hundred twenty-one trillion, two hundred twelve billion, one hundred twelve million, two hundred twenty-two thousand, two hundred twenty-one".