21123310022021 has 2 divisors, whose sum is σ = 21123310022022. Its totient is φ = 21123310022020.

The previous prime is 21123310021841. The next prime is 21123310022039. The reversal of 21123310022021 is 12022001332112.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 18159785644900 + 2963524377121 = 4261430^2 + 1721489^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-21123310022021 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 21123310021984 and 21123310022002.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21123310022921) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10561655011010 + 10561655011011.

It is an arithmetic number, because the mean of its divisors is an integer number (10561655011011).

Almost surely, 2^{21123310022021} is an apocalyptic number.

It is an amenable number.

21123310022021 is a deficient number, since it is larger than the sum of its proper divisors (1).

21123310022021 is an equidigital number, since it uses as much as digits as its factorization.

21123310022021 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 288, while the sum is 20.

Adding to 21123310022021 its reverse (12022001332112), we get a palindrome (33145311354133).

The spelling of 21123310022021 in words is "twenty-one trillion, one hundred twenty-three billion, three hundred ten million, twenty-two thousand, twenty-one".