210242309 has 2 divisors, whose sum is σ = 210242310. Its totient is φ = 210242308.

The previous prime is 210242269. The next prime is 210242317. The reversal of 210242309 is 903242012.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 182385025 + 27857284 = 13505^2 + 5278^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-210242309 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (210245309) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 105121154 + 105121155.

It is an arithmetic number, because the mean of its divisors is an integer number (105121155).

Almost surely, 2^210242309 is an apocalyptic number.

It is an amenable number.

210242309 is a deficient number, since it is larger than the sum of its proper divisors (1).

210242309 is an equidigital number, since it uses as much as digits as its factorization.

210242309 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 864, while the sum is 23.

The square root of 210242309 is about 14499.7347906781. The cubic root of 210242309 is about 594.6207210204.

The spelling of 210242309 in words is "two hundred ten million, two hundred forty-two thousand, three hundred nine".