21000221011009 has 2 divisors, whose sum is σ = 21000221011010. Its totient is φ = 21000221011008.

The previous prime is 21000221010991. The next prime is 21000221011027. The reversal of 21000221011009 is 90011012200012.

It is a happy number.

It is a balanced prime because it is at equal distance from previous prime (21000221010991) and next prime (21000221011027).

It can be written as a sum of positive squares in only one way, i.e., 20320684575409 + 679536435600 = 4507847^2 + 824340^2 .

It is a cyclic number.

It is not a de Polignac number, because 21000221011009 - 2²¹ = 21000218913857 is a prime.

It is a super-2 number, since 2×21000221011009² (a number of 27 digits) contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (21000221011109) 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, 10500110505504 + 10500110505505.

It is an arithmetic number, because the mean of its divisors is an integer number (10500110505505).

Almost surely, 2^{21000221011009} is an apocalyptic number.

It is an amenable number.

21000221011009 is a deficient number, since it is larger than the sum of its proper divisors (1).

21000221011009 is an equidigital number, since it uses as much as digits as its factorization.

21000221011009 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 19.

The spelling of 21000221011009 in words is "twenty-one trillion, two hundred twenty-one million, eleven thousand, nine".