211211989 has 2 divisors, whose sum is σ = 211211990. Its totient is φ = 211211988.

The previous prime is 211211983. The next prime is 211212011. The reversal of 211211989 is 989112112.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 208571364 + 2640625 = 14442^2 + 1625^2 .

It is a cyclic number.

It is not a de Polignac number, because 211211989 - 2¹¹ = 211209941 is a prime.

It is a super-2 number, since 2×211211989² = 89221008594672242, which contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (211211983) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 105605994 + 105605995.

It is an arithmetic number, because the mean of its divisors is an integer number (105605995).

Almost surely, 2^211211989 is an apocalyptic number.

It is an amenable number.

211211989 is a deficient number, since it is larger than the sum of its proper divisors (1).

211211989 is an equidigital number, since it uses as much as digits as its factorization.

211211989 is an evil number, because the sum of its binary digits is even.

The product of its digits is 2592, while the sum is 34.

The square root of 211211989 is about 14533.1341767700. The cubic root of 211211989 is about 595.5334894593.

The spelling of 211211989 in words is "two hundred eleven million, two hundred eleven thousand, nine hundred eighty-nine".