211969 has 2 divisors, whose sum is σ = 211970. Its totient is φ = 211968.

The previous prime is 211949. The next prime is 211979. The reversal of 211969 is 969112.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 129600 + 82369 = 360^2 + 287^2 .

It is a cyclic number.

It is not a de Polignac number, because 211969 - 2⁹ = 211457 is a prime.

It is a super-2 number, since 2×211969² = 89861713922, which contains 22 as substring.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (211949) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (7) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 105984 + 105985.

It is an arithmetic number, because the mean of its divisors is an integer number (105985).

It is a Proth number, since it is equal to 207 ⋅ 2¹⁰ + 1 and 207 < 2¹⁰.

2²¹¹⁹⁶⁹ is an apocalyptic number.

It is an amenable number.

211969 is a deficient number, since it is larger than the sum of its proper divisors (1).

211969 is an equidigital number, since it uses as much as digits as its factorization.

211969 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 972, while the sum is 28.

The square root of 211969 is about 460.4009122493. The cubic root of 211969 is about 59.6244130727.

The spelling of 211969 in words is "two hundred eleven thousand, nine hundred sixty-nine".