2005657 has 4 divisors (see below), whose sum is σ = 2016036. Its totient is φ = 1995280.

The previous prime is 2005613. The next prime is 2005667. The reversal of 2005657 is 7565002.

It is a happy number.

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 1679616 + 326041 = 1296^2 + 571^2 .

It is a cyclic number.

It is not a de Polignac number, because 2005657 - 2¹⁵ = 1972889 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (2005667) 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, 4894 + ... + 5287.

It is an arithmetic number, because the mean of its divisors is an integer number (504009).

2^2005657 is an apocalyptic number.

It is an amenable number.

2005657 is a deficient number, since it is larger than the sum of its proper divisors (10379).

2005657 is a wasteful number, since it uses less digits than its factorization.

2005657 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 10378.

The product of its (nonzero) digits is 2100, while the sum is 25.

The square root of 2005657 is about 1416.2122016139. The cubic root of 2005657 is about 126.1107827227.

It can be divided in two parts, 2005 and 657, that added together give a palindrome (2662).

The spelling of 2005657 in words is "two million, five thousand, six hundred fifty-seven".