1242428861 has 2 divisors, whose sum is σ = 1242428862. Its totient is φ = 1242428860.

The previous prime is 1242428827. The next prime is 1242428897. The reversal of 1242428861 is 1688242421.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 1188111961 + 54316900 = 34469^2 + 7370^2 .

It is an emirp because it is prime and its reverse (1688242421) is a distict prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-1242428861 is a prime.

It is a Sophie Germain prime.

It is a Curzon number.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (1242428801) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 621214430 + 621214431.

It is an arithmetic number, because the mean of its divisors is an integer number (621214431).

Almost surely, 2^1242428861 is an apocalyptic number.

It is an amenable number.

1242428861 is a deficient number, since it is larger than the sum of its proper divisors (1).

1242428861 is an equidigital number, since it uses as much as digits as its factorization.

1242428861 is an evil number, because the sum of its binary digits is even.

The product of its digits is 49152, while the sum is 38.

The square root of 1242428861 is about 35248.1043603766. The cubic root of 1242428861 is about 1075.0380692485.

The spelling of 1242428861 in words is "one billion, two hundred forty-two million, four hundred twenty-eight thousand, eight hundred sixty-one".