211489021 has 2 divisors, whose sum is σ = 211489022. Its totient is φ = 211489020.

The previous prime is 211488997. The next prime is 211489039. The reversal of 211489021 is 120984112.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 174108025 + 37380996 = 13195^2 + 6114^2 .

It is a cyclic number.

It is not a de Polignac number, because 211489021 - 2⁵ = 211488989 is a prime.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (211489121) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 105744510 + 105744511.

It is an arithmetic number, because the mean of its divisors is an integer number (105744511).

Almost surely, 2^211489021 is an apocalyptic number.

It is an amenable number.

211489021 is a deficient number, since it is larger than the sum of its proper divisors (1).

211489021 is an equidigital number, since it uses as much as digits as its factorization.

211489021 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 1152, while the sum is 28.

The square root of 211489021 is about 14542.6621015549. The cubic root of 211489021 is about 595.7937489191.

The spelling of 211489021 in words is "two hundred eleven million, four hundred eighty-nine thousand, twenty-one".