242658781 has 2 divisors, whose sum is σ = 242658782. Its totient is φ = 242658780.

The previous prime is 242658749. The next prime is 242658811. The reversal of 242658781 is 187856242.

It is a happy number.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 135722500 + 106936281 = 11650^2 + 10341^2 .

It is a cyclic number.

It is not a de Polignac number, because 242658781 - 2⁵ = 242658749 is a prime.

It is a super-2 number, since 2×242658781² = 117766567992811922, which contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (242658701) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 121329390 + 121329391.

It is an arithmetic number, because the mean of its divisors is an integer number (121329391).

Almost surely, 2^242658781 is an apocalyptic number.

It is an amenable number.

242658781 is a deficient number, since it is larger than the sum of its proper divisors (1).

242658781 is an equidigital number, since it uses as much as digits as its factorization.

242658781 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 215040, while the sum is 43.

The square root of 242658781 is about 15577.5088188067. The cubic root of 242658781 is about 623.7329260938.

The spelling of 242658781 in words is "two hundred forty-two million, six hundred fifty-eight thousand, seven hundred eighty-one".