211021202009 has 2 divisors, whose sum is σ = 211021202010. Its totient is φ = 211021202008.

The previous prime is 211021201999. The next prime is 211021202027. The reversal of 211021202009 is 900202120112.

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., 169904718025 + 41116483984 = 412195^2 + 202772^2 .

It is a cyclic number.

It is not a de Polignac number, because 211021202009 - 2⁸ = 211021201753 is a prime.

It is not a weakly prime, because it can be changed into another prime (211021202089) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 105510601004 + 105510601005.

It is an arithmetic number, because the mean of its divisors is an integer number (105510601005).

Almost surely, 2^211021202009 is an apocalyptic number.

It is an amenable number.

211021202009 is a deficient number, since it is larger than the sum of its proper divisors (1).

211021202009 is an equidigital number, since it uses as much as digits as its factorization.

211021202009 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 144, while the sum is 20.

The spelling of 211021202009 in words is "two hundred eleven billion, twenty-one million, two hundred two thousand, nine".