1665312165 has 24 divisors (see below), whose sum is σ = 3148954848. Its totient is φ = 807423840.

The previous prime is 1665312161. The next prime is 1665312167. The reversal of 1665312165 is 5612135661.

1665312165 is a `hidden beast` number, since 1 + 66 + 531 + 2 + 1 + 65 = 666.

It is not a de Polignac number, because 1665312165 - 2² = 1665312161 is a prime.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1665312161) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 1681639 + ... + 1682628.

It is an arithmetic number, because the mean of its divisors is an integer number (131206452).

Almost surely, 2^1665312165 is an apocalyptic number.

1665312165 is a gapful number since it is divisible by the number (15) formed by its first and last digit.

It is an amenable number.

1665312165 is a deficient number, since it is larger than the sum of its proper divisors (1483642683).

1665312165 is a wasteful number, since it uses less digits than its factorization.

1665312165 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3364289 (or 3364286 counting only the distinct ones).

The product of its digits is 32400, while the sum is 36.

The square root of 1665312165 is about 40808.2364848078. The cubic root of 1665312165 is about 1185.3098265869.

The spelling of 1665312165 in words is "one billion, six hundred sixty-five million, three hundred twelve thousand, one hundred sixty-five".