211721249 has 2 divisors, whose sum is σ = 211721250. Its totient is φ = 211721248.

The previous prime is 211721239. The next prime is 211721303. The reversal of 211721249 is 942127112.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 174900625 + 36820624 = 13225^2 + 6068^2 .

It is a cyclic number.

It is not a de Polignac number, because 211721249 - 2²⁴ = 194944033 is a prime.

It is not a weakly prime, because it can be changed into another prime (211721239) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 105860624 + 105860625.

It is an arithmetic number, because the mean of its divisors is an integer number (105860625).

Almost surely, 2^211721249 is an apocalyptic number.

It is an amenable number.

211721249 is a deficient number, since it is larger than the sum of its proper divisors (1).

211721249 is an equidigital number, since it uses as much as digits as its factorization.

211721249 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 2016, while the sum is 29.

The square root of 211721249 is about 14550.6442812681. The cubic root of 211721249 is about 596.0117419199.

The spelling of 211721249 in words is "two hundred eleven million, seven hundred twenty-one thousand, two hundred forty-nine".