121212202221 has 48 divisors (see below), whose sum is σ = 198323536320. Its totient is φ = 73369825920.

The previous prime is 121212202211. The next prime is 121212202289. The reversal of 121212202221 is 122202212121.

It is a happy number.

It is not a de Polignac number, because 121212202221 - 2⁶ = 121212202157 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 121212202194 and 121212202203.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (121212202211) by changing a digit.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 2134431 + ... + 2190483.

It is an arithmetic number, because the mean of its divisors is an integer number (4131740340).

Almost surely, 2^121212202221 is an apocalyptic number.

121212202221 is a gapful number since it is divisible by the number (11) formed by its first and last digit.

It is an amenable number.

121212202221 is a deficient number, since it is larger than the sum of its proper divisors (77111334099).

121212202221 is an equidigital number, since it uses as much as digits as its factorization.

121212202221 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 56888 (or 56876 counting only the distinct ones).

The product of its (nonzero) digits is 128, while the sum is 18.

Adding to 121212202221 its reverse (122202212121), we get a palindrome (243414414342).

The spelling of 121212202221 in words is "one hundred twenty-one billion, two hundred twelve million, two hundred two thousand, two hundred twenty-one".