847981 has 4 divisors (see below), whose sum is σ = 849852. Its totient is φ = 846112.

The previous prime is 847969. The next prime is 847991. The reversal of 847981 is 189748.

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

It can be written as a sum of positive squares in 2 ways, for example, as 133956 + 714025 = 366^2 + 845^2 .

It is a cyclic number.

It is not a de Polignac number, because 847981 - 2⁵ = 847949 is a prime.

It is a super-2 number, since 2×847981² = 1438143552722, which contains 22 as substring.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 847981.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (847901) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 225 + ... + 1321.

It is an arithmetic number, because the mean of its divisors is an integer number (212463).

2⁸⁴⁷⁹⁸¹ is an apocalyptic number.

It is an amenable number.

847981 is a deficient number, since it is larger than the sum of its proper divisors (1871).

847981 is a wasteful number, since it uses less digits than its factorization.

847981 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1870.

The product of its digits is 16128, while the sum is 37.

The square root of 847981 is about 920.8588382592. The cubic root of 847981 is about 94.6517629010.

The spelling of 847981 in words is "eight hundred forty-seven thousand, nine hundred eighty-one".