21020112202121 has 2 divisors, whose sum is σ = 21020112202122. Its totient is φ = 21020112202120.

The previous prime is 21020112202109. The next prime is 21020112202153. The reversal of 21020112202121 is 12120221102012.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 11975440908025 + 9044671294096 = 3460555^2 + 3007436^2 .

It is a cyclic number.

It is not a de Polignac number, because 21020112202121 - 2¹⁸ = 21020111939977 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 21020112202121.

It is not a weakly prime, because it can be changed into another prime (21020112222121) 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, 10510056101060 + 10510056101061.

It is an arithmetic number, because the mean of its divisors is an integer number (10510056101061).

Almost surely, 2^{21020112202121} is an apocalyptic number.

It is an amenable number.

21020112202121 is a deficient number, since it is larger than the sum of its proper divisors (1).

21020112202121 is an equidigital number, since it uses as much as digits as its factorization.

21020112202121 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 17.

Adding to 21020112202121 its reverse (12120221102012), we get a palindrome (33140333304133).

The spelling of 21020112202121 in words is "twenty-one trillion, twenty billion, one hundred twelve million, two hundred two thousand, one hundred twenty-one".