242987861 has 2 divisors, whose sum is σ = 242987862. Its totient is φ = 242987860.

The previous prime is 242987821. The next prime is 242987867. The reversal of 242987861 is 168789242.

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., 225930961 + 17056900 = 15031^2 + 4130^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-242987861 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 (242987867) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 121493930 + 121493931.

It is an arithmetic number, because the mean of its divisors is an integer number (121493931).

Almost surely, 2^242987861 is an apocalyptic number.

It is an amenable number.

242987861 is a deficient number, since it is larger than the sum of its proper divisors (1).

242987861 is an equidigital number, since it uses as much as digits as its factorization.

242987861 is an evil number, because the sum of its binary digits is even.

The product of its digits is 387072, while the sum is 47.

The square root of 242987861 is about 15588.0679046507. The cubic root of 242987861 is about 624.0147557394.

The spelling of 242987861 in words is "two hundred forty-two million, nine hundred eighty-seven thousand, eight hundred sixty-one".