211342309 has 2 divisors, whose sum is σ = 211342310. Its totient is φ = 211342308.

The previous prime is 211342303. The next prime is 211342333. The reversal of 211342309 is 903243112.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 180150084 + 31192225 = 13422^2 + 5585^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-211342309 is a prime.

It is equal to p_11671540 and since 211342309 and 11671540 have the same sum of digits, it is a Honaker prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (211342303) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 105671154 + 105671155.

It is an arithmetic number, because the mean of its divisors is an integer number (105671155).

Almost surely, 2^211342309 is an apocalyptic number.

It is an amenable number.

211342309 is a deficient number, since it is larger than the sum of its proper divisors (1).

211342309 is an equidigital number, since it uses as much as digits as its factorization.

211342309 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 1296, while the sum is 25.

The square root of 211342309 is about 14537.6170330629. The cubic root of 211342309 is about 595.6559477348.

The spelling of 211342309 in words is "two hundred eleven million, three hundred forty-two thousand, three hundred nine".