121001111221 has 2 divisors, whose sum is σ = 121001111222. Its totient is φ = 121001111220.

The previous prime is 121001111201. The next prime is 121001111227. The reversal of 121001111221 is 122111100121.

It is a happy number.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 72153480996 + 48847630225 = 268614^2 + 221015^2 .

It is a cyclic number.

It is not a de Polignac number, because 121001111221 - 2³³ = 112411176629 is a prime.

It is a super-2 number, since 2×121001111221² (a number of 23 digits) contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (121001111227) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 60500555610 + 60500555611.

It is an arithmetic number, because the mean of its divisors is an integer number (60500555611).

Almost surely, 2^121001111221 is an apocalyptic number.

It is an amenable number.

121001111221 is a deficient number, since it is larger than the sum of its proper divisors (1).

121001111221 is an equidigital number, since it uses as much as digits as its factorization.

121001111221 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 8, while the sum is 13.

Adding to 121001111221 its reverse (122111100121), we get a palindrome (243112211342).

The spelling of 121001111221 in words is "one hundred twenty-one billion, one million, one hundred eleven thousand, two hundred twenty-one".