211121009989 has 2 divisors, whose sum is σ = 211121009990. Its totient is φ = 211121009988.

The previous prime is 211121009971. The next prime is 211121010011. The reversal of 211121009989 is 989900121112.

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., 147897930625 + 63223079364 = 384575^2 + 251442^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-211121009989 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (211121009189) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 105560504994 + 105560504995.

It is an arithmetic number, because the mean of its divisors is an integer number (105560504995).

Almost surely, 2^211121009989 is an apocalyptic number.

It is an amenable number.

211121009989 is a deficient number, since it is larger than the sum of its proper divisors (1).

211121009989 is an equidigital number, since it uses as much as digits as its factorization.

211121009989 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 23328, while the sum is 43.

The spelling of 211121009989 in words is "two hundred eleven billion, one hundred twenty-one million, nine thousand, nine hundred eighty-nine".