211240247 has 2 divisors, whose sum is σ = 211240248. Its totient is φ = 211240246.

The previous prime is 211240217. The next prime is 211240259. The reversal of 211240247 is 742042112.

It is a strong prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-211240247 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (211240207) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 105620123 + 105620124.

It is an arithmetic number, because the mean of its divisors is an integer number (105620124).

Almost surely, 2^211240247 is an apocalyptic number.

211240247 is a deficient number, since it is larger than the sum of its proper divisors (1).

211240247 is an equidigital number, since it uses as much as digits as its factorization.

211240247 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 896, while the sum is 23.

The square root of 211240247 is about 14534.1063364763. The cubic root of 211240247 is about 595.5600470346.

Adding to 211240247 its reverse (742042112), we get a palindrome (953282359).

The spelling of 211240247 in words is "two hundred eleven million, two hundred forty thousand, two hundred forty-seven".