121221210111221 has 16 divisors (see below), whose sum is σ = 136510153022976. Its totient is φ = 106643894760000.

The previous prime is 121221210111137. The next prime is 121221210111233. The reversal of 121221210111221 is 122111012122121.

It is a happy number.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-121221210111221 is a prime.

It is a super-2 number, since 2×121221210111221² (a number of 29 digits) contains 22 as substring.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 121221210111193 and 121221210111202.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (121221210111241) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 11830931 + ... + 19555391.

It is an arithmetic number, because the mean of its divisors is an integer number (8531884563936).

Almost surely, 2^{121221210111221} is an apocalyptic number.

121221210111221 is a gapful number since it is divisible by the number (11) formed by its first and last digit.

It is an amenable number.

121221210111221 is a deficient number, since it is larger than the sum of its proper divisors (15288942911755).

121221210111221 is a wasteful number, since it uses less digits than its factorization.

121221210111221 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 7770524.

The product of its (nonzero) digits is 64, while the sum is 20.

Adding to 121221210111221 its reverse (122111012122121), we get a palindrome (243332222233342).

The spelling of 121221210111221 in words is "one hundred twenty-one trillion, two hundred twenty-one billion, two hundred ten million, one hundred eleven thousand, two hundred twenty-one".