5661665 has 4 divisors (see below), whose sum is σ = 6794004. Its totient is φ = 4529328.

The previous prime is 5661659. The next prime is 5661673.

5661665 is nontrivially palindromic in base 10.

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 4231249 + 1430416 = 2057^2 + 1196^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-5661665 is a prime.

It is a Duffinian number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 566162 + ... + 566171.

It is an arithmetic number, because the mean of its divisors is an integer number (1698501).

Almost surely, 2^5661665 is an apocalyptic number.

It is an amenable number.

5661665 is a deficient number, since it is larger than the sum of its proper divisors (1132339).

5661665 is a wasteful number, since it uses less digits than its factorization.

5661665 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1132338.

The product of its digits is 32400, while the sum is 35.

The square root of 5661665 is about 2379.4253507938. The cubic root of 5661665 is about 178.2302390318.

Subtracting from 5661665 its product of digits (32400), we obtain a palindrome (5629265).

The spelling of 5661665 in words is "five million, six hundred sixty-one thousand, six hundred sixty-five".