21221122201021 has 2 divisors, whose sum is σ = 21221122201022. Its totient is φ = 21221122201020.

The previous prime is 21221122201009. The next prime is 21221122201033. The reversal of 21221122201021 is 12010222112212.

It is a balanced prime because it is at equal distance from previous prime (21221122201009) and next prime (21221122201033).

It can be written as a sum of positive squares in only one way, i.e., 21155630225625 + 65491975396 = 4599525^2 + 255914^2 .

It is a cyclic number.

It is not a de Polignac number, because 21221122201021 - 2⁴³ = 12425029178813 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 21221122201021.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21221122201061) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10610561100510 + 10610561100511.

It is an arithmetic number, because the mean of its divisors is an integer number (10610561100511).

Almost surely, 2^{21221122201021} is an apocalyptic number.

It is an amenable number.

21221122201021 is a deficient number, since it is larger than the sum of its proper divisors (1).

21221122201021 is an equidigital number, since it uses as much as digits as its factorization.

21221122201021 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 128, while the sum is 19.

Adding to 21221122201021 its reverse (12010222112212), we get a palindrome (33231344313233).

The spelling of 21221122201021 in words is "twenty-one trillion, two hundred twenty-one billion, one hundred twenty-two million, two hundred one thousand, twenty-one".