212113309 has 2 divisors, whose sum is σ = 212113310. Its totient is φ = 212113308.

The previous prime is 212113247. The next prime is 212113313. The reversal of 212113309 is 903311212.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 209380900 + 2732409 = 14470^2 + 1653^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-212113309 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 212113309.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (212113379) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 106056654 + 106056655.

It is an arithmetic number, because the mean of its divisors is an integer number (106056655).

Almost surely, 2^212113309 is an apocalyptic number.

It is an amenable number.

212113309 is a deficient number, since it is larger than the sum of its proper divisors (1).

212113309 is an equidigital number, since it uses as much as digits as its factorization.

212113309 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 324, while the sum is 22.

The square root of 212113309 is about 14564.1103058168. The cubic root of 212113309 is about 596.3794081740.

The spelling of 212113309 in words is "two hundred twelve million, one hundred thirteen thousand, three hundred nine".