242991257 has 2 divisors, whose sum is σ = 242991258. Its totient is φ = 242991256.

The previous prime is 242991239. The next prime is 242991263. The reversal of 242991257 is 752199242.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 197009296 + 45981961 = 14036^2 + 6781^2 .

It is a cyclic number.

It is not a de Polignac number, because 242991257 - 2²⁶ = 175882393 is a prime.

It is not a weakly prime, because it can be changed into another prime (242991227) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 121495628 + 121495629.

It is an arithmetic number, because the mean of its divisors is an integer number (121495629).

Almost surely, 2^242991257 is an apocalyptic number.

It is an amenable number.

242991257 is a deficient number, since it is larger than the sum of its proper divisors (1).

242991257 is an equidigital number, since it uses as much as digits as its factorization.

242991257 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 90720, while the sum is 41.

The square root of 242991257 is about 15588.1768337417. The cubic root of 242991257 is about 624.0176628041.

The spelling of 242991257 in words is "two hundred forty-two million, nine hundred ninety-one thousand, two hundred fifty-seven".