1665080217 has 12 divisors (see below), whose sum is σ = 2444544804. Its totient is φ = 1091855520.

The previous prime is 1665080203. The next prime is 1665080227. The reversal of 1665080217 is 7120805661.

It can be written as a sum of positive squares in 2 ways, for example, as 238054041 + 1427026176 = 15429^2 + 37776^2 .

It is a de Polignac number, because none of the positive numbers 2^k-1665080217 is a prime.

It is a Smith number, since the sum of its digits (36) coincides with the sum of the digits of its prime factors.

It is not an unprimeable number, because it can be changed into a prime (1665080227) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 1515918 + ... + 1517015.

It is an arithmetic number, because the mean of its divisors is an integer number (203712067).

Almost surely, 2^1665080217 is an apocalyptic number.

It is an amenable number.

1665080217 is a deficient number, since it is larger than the sum of its proper divisors (779464587).

1665080217 is a wasteful number, since it uses less digits than its factorization.

1665080217 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3033000 (or 3032997 counting only the distinct ones).

The product of its (nonzero) digits is 20160, while the sum is 36.

The square root of 1665080217 is about 40805.3944595564. The cubic root of 1665080217 is about 1185.2547932595.

Adding to 1665080217 its reverse (7120805661), we get a palindrome (8785885878).

The spelling of 1665080217 in words is "one billion, six hundred sixty-five million, eighty thousand, two hundred seventeen".