211997 has 2 divisors, whose sum is σ = 211998. Its totient is φ = 211996.

The previous prime is 211979. The next prime is 212029. The reversal of 211997 is 799112.

Together with previous prime (211979) it forms an Ormiston pair, because they use the same digits, order apart.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 148996 + 63001 = 386^2 + 251^2 .

It is a cyclic number.

It is not a de Polignac number, because 211997 - 2⁶ = 211933 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 (211927) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 105998 + 105999.

It is an arithmetic number, because the mean of its divisors is an integer number (105999).

2²¹¹⁹⁹⁷ is an apocalyptic number.

It is an amenable number.

211997 is a deficient number, since it is larger than the sum of its proper divisors (1).

211997 is an equidigital number, since it uses as much as digits as its factorization.

211997 is an evil number, because the sum of its binary digits is even.

The product of its digits is 1134, while the sum is 29.

The square root of 211997 is about 460.4313195255. The cubic root of 211997 is about 59.6270383152.

The spelling of 211997 in words is "two hundred eleven thousand, nine hundred ninety-seven".