1242889 has 2 divisors, whose sum is σ = 1242890. Its totient is φ = 1242888.

The previous prime is 1242869. The next prime is 1242893. The reversal of 1242889 is 9882421.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 705600 + 537289 = 840^2 + 733^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-1242889 is a prime.

It is not a weakly prime, because it can be changed into another prime (1242859) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 621444 + 621445.

It is an arithmetic number, because the mean of its divisors is an integer number (621445).

2^1242889 is an apocalyptic number.

It is an amenable number.

1242889 is a deficient number, since it is larger than the sum of its proper divisors (1).

1242889 is an equidigital number, since it uses as much as digits as its factorization.

1242889 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 9216, while the sum is 34.

The square root of 1242889 is about 1114.8493171725. The cubic root of 1242889 is about 107.5170767896.

The spelling of 1242889 in words is "one million, two hundred forty-two thousand, eight hundred eighty-nine".