2057809 has 4 divisors (see below), whose sum is σ = 2216116. Its totient is φ = 1899504.

The previous prime is 2057807. The next prime is 2057813. The reversal of 2057809 is 9087502.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 9087502 = 2 ⋅4543751.

It can be written as a sum of positive squares in 2 ways, for example, as 1113025 + 944784 = 1055^2 + 972^2 .

It is a cyclic number.

It is not a de Polignac number, because 2057809 - 2¹ = 2057807 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (2057807) 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, 79134 + ... + 79159.

It is an arithmetic number, because the mean of its divisors is an integer number (554029).

2^2057809 is an apocalyptic number.

It is an amenable number.

2057809 is a deficient number, since it is larger than the sum of its proper divisors (158307).

2057809 is a wasteful number, since it uses less digits than its factorization.

2057809 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 158306.

The product of its (nonzero) digits is 5040, while the sum is 31.

The square root of 2057809 is about 1434.5065353633. The cubic root of 2057809 is about 127.1945063421.

The spelling of 2057809 in words is "two million, fifty-seven thousand, eight hundred nine".