21012210100009 has 2 divisors, whose sum is σ = 21012210100010. Its totient is φ = 21012210100008.

The previous prime is 21012210099941. The next prime is 21012210100097. The reversal of 21012210100009 is 90000101221012.

It is a happy number.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 18910348051609 + 2101862048400 = 4348603^2 + 1449780^2 .

It is a cyclic number.

It is not a de Polignac number, because 21012210100009 - 2²⁹ = 21011673229097 is a prime.

It is not a weakly prime, because it can be changed into another prime (21012210100099) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10506105050004 + 10506105050005.

It is an arithmetic number, because the mean of its divisors is an integer number (10506105050005).

Almost surely, 2^{21012210100009} is an apocalyptic number.

It is an amenable number.

21012210100009 is a deficient number, since it is larger than the sum of its proper divisors (1).

21012210100009 is an equidigital number, since it uses as much as digits as its factorization.

21012210100009 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 72, while the sum is 19.

The spelling of 21012210100009 in words is "twenty-one trillion, twelve billion, two hundred ten million, one hundred thousand, nine".