211011221989 has 2 divisors, whose sum is σ = 211011221990. Its totient is φ = 211011221988.

The previous prime is 211011221987. The next prime is 211011222017. The reversal of 211011221989 is 989122110112.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 200674433089 + 10336788900 = 447967^2 + 101670^2 .

It is a cyclic number.

It is not a de Polignac number, because 211011221989 - 2¹ = 211011221987 is a prime.

It is a super-2 number, since 2×211011221989² (a number of 23 digits) contains 22 as substring.

Together with 211011221987, it forms a pair of twin primes.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (211011221987) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 105505610994 + 105505610995.

It is an arithmetic number, because the mean of its divisors is an integer number (105505610995).

Almost surely, 2^211011221989 is an apocalyptic number.

It is an amenable number.

211011221989 is a deficient number, since it is larger than the sum of its proper divisors (1).

211011221989 is an equidigital number, since it uses as much as digits as its factorization.

211011221989 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 5184, while the sum is 37.

The spelling of 211011221989 in words is "two hundred eleven billion, eleven million, two hundred twenty-one thousand, nine hundred eighty-nine".