1242739 has 2 divisors, whose sum is σ = 1242740. Its totient is φ = 1242738.

The previous prime is 1242643. The next prime is 1242757. The reversal of 1242739 is 9372421.

It is a strong prime.

It is an emirp because it is prime and its reverse (9372421) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 1242739 - 2⁷ = 1242611 is a prime.

It is not a weakly prime, because it can be changed into another prime (1240739) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a good prime.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 621369 + 621370.

It is an arithmetic number, because the mean of its divisors is an integer number (621370).

2^1242739 is an apocalyptic number.

1242739 is a deficient number, since it is larger than the sum of its proper divisors (1).

1242739 is an equidigital number, since it uses as much as digits as its factorization.

1242739 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 3024, while the sum is 28.

The square root of 1242739 is about 1114.7820414772. The cubic root of 1242739 is about 107.5127513268.

The spelling of 1242739 in words is "one million, two hundred forty-two thousand, seven hundred thirty-nine".