21011101201021 has 2 divisors, whose sum is σ = 21011101201022. Its totient is φ = 21011101201020.

The previous prime is 21011101200997. The next prime is 21011101201033. The reversal of 21011101201021 is 12010210111012.

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., 20163018605625 + 848082595396 = 4490325^2 + 920914^2 .

It is a cyclic number.

It is not a de Polignac number, because 21011101201021 - 2¹¹ = 21011101198973 is a prime.

It is a super-2 number, since 2×21011101201021² (a number of 27 digits) contains 22 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 21011101200992 and 21011101201010.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21011101201421) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10505550600510 + 10505550600511.

It is an arithmetic number, because the mean of its divisors is an integer number (10505550600511).

Almost surely, 2^{21011101201021} is an apocalyptic number.

It is an amenable number.

21011101201021 is a deficient number, since it is larger than the sum of its proper divisors (1).

21011101201021 is an equidigital number, since it uses as much as digits as its factorization.

21011101201021 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 21011101201021 its reverse (12010210111012), we get a palindrome (33021311312033).

The spelling of 21011101201021 in words is "twenty-one trillion, eleven billion, one hundred one million, two hundred one thousand, twenty-one".