1242805 has 16 divisors (see below), whose sum is σ = 1586304. Its totient is φ = 932800.

The previous prime is 1242803. The next prime is 1242811. The reversal of 1242805 is 5082421.

It is not a de Polignac number, because 1242805 - 2¹ = 1242803 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1242803) 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 in 15 ways as a sum of consecutive naturals, for example, 11562 + ... + 11668.

It is an arithmetic number, because the mean of its divisors is an integer number (99144).

2^1242805 is an apocalyptic number.

It is an amenable number.

1242805 is a deficient number, since it is larger than the sum of its proper divisors (343499).

1242805 is a wasteful number, since it uses less digits than its factorization.

1242805 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 236.

The product of its (nonzero) digits is 640, while the sum is 22.

The square root of 1242805 is about 1114.8116432833. The cubic root of 1242805 is about 107.5146545733.

The spelling of 1242805 in words is "one million, two hundred forty-two thousand, eight hundred five".