21020122021009 has 2 divisors, whose sum is σ = 21020122021010. Its totient is φ = 21020122021008.

The previous prime is 21020122020979. The next prime is 21020122021033. The reversal of 21020122021009 is 90012022102012.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 14346269796609 + 6673852224400 = 3787647^2 + 2583380^2 .

It is a cyclic number.

It is not a de Polignac number, because 21020122021009 - 2⁷ = 21020122020881 is a prime.

It is not a weakly prime, because it can be changed into another prime (21020122021039) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10510061010504 + 10510061010505.

It is an arithmetic number, because the mean of its divisors is an integer number (10510061010505).

Almost surely, 2^{21020122021009} is an apocalyptic number.

It is an amenable number.

21020122021009 is a deficient number, since it is larger than the sum of its proper divisors (1).

21020122021009 is an equidigital number, since it uses as much as digits as its factorization.

21020122021009 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 288, while the sum is 22.

The spelling of 21020122021009 in words is "twenty-one trillion, twenty billion, one hundred twenty-two million, twenty-one thousand, nine".