1221122200021 has 2 divisors, whose sum is σ = 1221122200022. Its totient is φ = 1221122200020.

The previous prime is 1221122199929. The next prime is 1221122200079. The reversal of 1221122200021 is 1200022211221.

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., 1143004744996 + 78117455025 = 1069114^2 + 279495^2 .

It is a cyclic number.

It is not a de Polignac number, because 1221122200021 - 2¹⁵ = 1221122167253 is a prime.

It is a super-2 number, since 2×1221122200021² (a number of 25 digits) contains 22 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 1221122199968 and 1221122200004.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (1221122200121) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 610561100010 + 610561100011.

It is an arithmetic number, because the mean of its divisors is an integer number (610561100011).

Almost surely, 2^{1221122200021} is an apocalyptic number.

It is an amenable number.

1221122200021 is a deficient number, since it is larger than the sum of its proper divisors (1).

1221122200021 is an equidigital number, since it uses as much as digits as its factorization.

1221122200021 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 64, while the sum is 16.

Adding to 1221122200021 its reverse (1200022211221), we get a palindrome (2421144411242).

The spelling of 1221122200021 in words is "one trillion, two hundred twenty-one billion, one hundred twenty-two million, two hundred thousand, twenty-one".