211221469 has 2 divisors, whose sum is σ = 211221470. Its totient is φ = 211221468.

The previous prime is 211221421. The next prime is 211221473. The reversal of 211221469 is 964122112.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 207072100 + 4149369 = 14390^2 + 2037^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-211221469 is a prime.

It is a super-2 number, since 2×211221469² = 89229017933035922, which contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (211221169) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 105610734 + 105610735.

It is an arithmetic number, because the mean of its divisors is an integer number (105610735).

Almost surely, 2^211221469 is an apocalyptic number.

It is an amenable number.

211221469 is a deficient number, since it is larger than the sum of its proper divisors (1).

211221469 is an equidigital number, since it uses as much as digits as its factorization.

211221469 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 1728, while the sum is 28.

The square root of 211221469 is about 14533.4603243687. The cubic root of 211221469 is about 595.5423992645.

The spelling of 211221469 in words is "two hundred eleven million, two hundred twenty-one thousand, four hundred sixty-nine".