121111212220221 has 32 divisors (see below), whose sum is σ = 168537364704000. Its totient is φ = 77262589006848.

The previous prime is 121111212220213. The next prime is 121111212220283. The reversal of 121111212220221 is 122022212111121.

It is not a de Polignac number, because 121111212220221 - 2³ = 121111212220213 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (121111212220121) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 187144320 + ... + 187790358.

It is an arithmetic number, because the mean of its divisors is an integer number (5266792647000).

Almost surely, 2^{121111212220221} is an apocalyptic number.

It is an amenable number.

121111212220221 is a deficient number, since it is larger than the sum of its proper divisors (47426152483779).

121111212220221 is a wasteful number, since it uses less digits than its factorization.

121111212220221 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 665253.

The product of its (nonzero) digits is 128, while the sum is 21.

Adding to 121111212220221 its reverse (122022212111121), we get a palindrome (243133424331342).

The spelling of 121111212220221 in words is "one hundred twenty-one trillion, one hundred eleven billion, two hundred twelve million, two hundred twenty thousand, two hundred twenty-one".