842557 has 4 divisors (see below), whose sum is σ = 854496. Its totient is φ = 830620.

The previous prime is 842551. The next prime is 842581. The reversal of 842557 is 755248.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-842557 is a prime.

It is a Smith number, since the sum of its digits (31) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (842551) 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 3 ways as a sum of consecutive naturals, for example, 5863 + ... + 6004.

It is an arithmetic number, because the mean of its divisors is an integer number (213624).

2⁸⁴²⁵⁵⁷ is an apocalyptic number.

It is an amenable number.

842557 is a deficient number, since it is larger than the sum of its proper divisors (11939).

842557 is a wasteful number, since it uses less digits than its factorization.

842557 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 11938.

The product of its digits is 11200, while the sum is 31.

The square root of 842557 is about 917.9090368876. The cubic root of 842557 is about 94.4495218595.

The spelling of 842557 in words is "eight hundred forty-two thousand, five hundred fifty-seven".