2081857 has 4 divisors (see below), whose sum is σ = 2132676. Its totient is φ = 2031040.

The previous prime is 2081851. The next prime is 2081861. The reversal of 2081857 is 7581802.

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 863041 + 1218816 = 929^2 + 1104^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-2081857 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.

2081857 is a lucky number.

It is not an unprimeable number, because it can be changed into a prime (2081851) 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, 25348 + ... + 25429.

It is an arithmetic number, because the mean of its divisors is an integer number (533169).

2^2081857 is an apocalyptic number.

It is an amenable number.

2081857 is a deficient number, since it is larger than the sum of its proper divisors (50819).

2081857 is an equidigital number, since it uses as much as digits as its factorization.

2081857 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 50818.

The product of its (nonzero) digits is 4480, while the sum is 31.

The square root of 2081857 is about 1442.8641654709. The cubic root of 2081857 is about 127.6880628523.

Subtracting 2081857 from its reverse (7581802), we obtain a palindrome (5499945).

The spelling of 2081857 in words is "two million, eighty-one thousand, eight hundred fifty-seven".