1242781 has 2 divisors, whose sum is σ = 1242782. Its totient is φ = 1242780.

The previous prime is 1242767. The next prime is 1242803. The reversal of 1242781 is 1872421.

It is a happy number.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 793881 + 448900 = 891^2 + 670^2 .

It is an emirp because it is prime and its reverse (1872421) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 1242781 - 2¹⁹ = 718493 is a prime.

It is a super-2 number, since 2×1242781² = 3089009227922, which contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (1242181) by changing a digit.

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

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 621390 + 621391.

It is an arithmetic number, because the mean of its divisors is an integer number (621391).

2^1242781 is an apocalyptic number.

It is an amenable number.

1242781 is a deficient number, since it is larger than the sum of its proper divisors (1).

1242781 is an equidigital number, since it uses as much as digits as its factorization.

1242781 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 896, while the sum is 25.

The square root of 1242781 is about 1114.8008790811. The cubic root of 1242781 is about 107.5139624915.

The spelling of 1242781 in words is "one million, two hundred forty-two thousand, seven hundred eighty-one".