212304509 has 2 divisors, whose sum is σ = 212304510. Its totient is φ = 212304508.

The previous prime is 212304451. The next prime is 212304511. The reversal of 212304509 is 905403212.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 189475225 + 22829284 = 13765^2 + 4778^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-212304509 is a prime.

Together with 212304511, it forms a pair of twin primes.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (212304529) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 106152254 + 106152255.

It is an arithmetic number, because the mean of its divisors is an integer number (106152255).

Almost surely, 2^212304509 is an apocalyptic number.

It is an amenable number.

212304509 is a deficient number, since it is larger than the sum of its proper divisors (1).

212304509 is an equidigital number, since it uses as much as digits as its factorization.

212304509 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 2160, while the sum is 26.

The square root of 212304509 is about 14570.6729082771. The cubic root of 212304509 is about 596.5585474884.

The spelling of 212304509 in words is "two hundred twelve million, three hundred four thousand, five hundred nine".