21012010211009 has 2 divisors, whose sum is σ = 21012010211010. Its totient is φ = 21012010211008.

The previous prime is 21012010210991. The next prime is 21012010211039. The reversal of 21012010211009 is 90011201021012.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 18311338680625 + 2700671530384 = 4279175^2 + 1643372^2 .

It is a cyclic number.

It is not a de Polignac number, because 21012010211009 - 2¹⁶ = 21012010145473 is a prime.

It is not a weakly prime, because it can be changed into another prime (21012010211039) 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, 10506005105504 + 10506005105505.

It is an arithmetic number, because the mean of its divisors is an integer number (10506005105505).

Almost surely, 2^{21012010211009} is an apocalyptic number.

It is an amenable number.

21012010211009 is a deficient number, since it is larger than the sum of its proper divisors (1).

21012010211009 is an equidigital number, since it uses as much as digits as its factorization.

21012010211009 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 72, while the sum is 20.

The spelling of 21012010211009 in words is "twenty-one trillion, twelve billion, ten million, two hundred eleven thousand, nine".