981857 has 4 divisors (see below), whose sum is σ = 990660. Its totient is φ = 973056.

The previous prime is 981823. The next prime is 981887. The reversal of 981857 is 758189.

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 398161 + 583696 = 631^2 + 764^2 .

It is a cyclic number.

It is not a de Polignac number, because 981857 - 2⁸ = 981601 is a prime.

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 981857.

It is not an unprimeable number, because it can be changed into a prime (981817) 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, 4232 + ... + 4457.

It is an arithmetic number, because the mean of its divisors is an integer number (247665).

2⁹⁸¹⁸⁵⁷ is an apocalyptic number.

It is an amenable number.

981857 is a deficient number, since it is larger than the sum of its proper divisors (8803).

981857 is a wasteful number, since it uses less digits than its factorization.

981857 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 8802.

The product of its digits is 20160, while the sum is 38.

The square root of 981857 is about 990.8869764004. The cubic root of 981857 is about 99.3915385894.

The spelling of 981857 in words is "nine hundred eighty-one thousand, eight hundred fifty-seven".