242120309 has 2 divisors, whose sum is σ = 242120310. Its totient is φ = 242120308.

The previous prime is 242120299. The next prime is 242120369. The reversal of 242120309 is 903021242.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 212722225 + 29398084 = 14585^2 + 5422^2 .

It is a cyclic number.

It is not a de Polignac number, because 242120309 - 2¹⁶ = 242054773 is a prime.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (242120369) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 121060154 + 121060155.

It is an arithmetic number, because the mean of its divisors is an integer number (121060155).

Almost surely, 2^242120309 is an apocalyptic number.

It is an amenable number.

242120309 is a deficient number, since it is larger than the sum of its proper divisors (1).

242120309 is an equidigital number, since it uses as much as digits as its factorization.

242120309 is an evil number, because the sum of its binary digits is even.

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

The square root of 242120309 is about 15560.2155833395. The cubic root of 242120309 is about 623.2712195313.

The spelling of 242120309 in words is "two hundred forty-two million, one hundred twenty thousand, three hundred nine".