842991 has 4 divisors (see below), whose sum is σ = 1123992. Its totient is φ = 561992.

The previous prime is 842987. The next prime is 842993. The reversal of 842991 is 199248.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 842991 - 2² = 842987 is a prime.

It is a D-number.

842991 is a lucky number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (842993) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 140496 + ... + 140501.

It is an arithmetic number, because the mean of its divisors is an integer number (280998).

2⁸⁴²⁹⁹¹ is an apocalyptic number.

842991 is a deficient number, since it is larger than the sum of its proper divisors (281001).

842991 is a wasteful number, since it uses less digits than its factorization.

842991 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 281000.

The product of its digits is 5184, while the sum is 33.

The square root of 842991 is about 918.1454133197. The cubic root of 842991 is about 94.4657360173.

The spelling of 842991 in words is "eight hundred forty-two thousand, nine hundred ninety-one".