121221111110021 has 8 divisors (see below), whose sum is σ = 130653434250360. Its totient is φ = 111804162581952.

The previous prime is 121221111110003. The next prime is 121221111110161. The reversal of 121221111110021 is 120011111122121.

It can be written as a sum of positive squares in 4 ways, for example, as 5219918061796 + 116001193048225 = 2284714^2 + 10770385^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 121221111110021 - 2⁶ = 121221111109957 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (121221111110221) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 3843636686 + ... + 3843668223.

It is an arithmetic number, because the mean of its divisors is an integer number (16331679281295).

Almost surely, 2^{121221111110021} is an apocalyptic number.

It is an amenable number.

121221111110021 is a deficient number, since it is larger than the sum of its proper divisors (9432323140339).

121221111110021 is a wasteful number, since it uses less digits than its factorization.

121221111110021 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 7687306135.

The product of its (nonzero) digits is 16, while the sum is 17.

Adding to 121221111110021 its reverse (120011111122121), we get a palindrome (241232222232142).

The spelling of 121221111110021 in words is "one hundred twenty-one trillion, two hundred twenty-one billion, one hundred eleven million, one hundred ten thousand, twenty-one".