1680512165 has 4 divisors (see below), whose sum is σ = 2016614604. Its totient is φ = 1344409728.

The previous prime is 1680512159. The next prime is 1680512177. The reversal of 1680512165 is 5612150861.

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 817445281 + 863066884 = 28591^2 + 29378^2 .

It is a cyclic number.

It is not a de Polignac number, because 1680512165 - 2⁸ = 1680511909 is a prime.

It is a super-2 number, since 2×1680512165² = 5648242273425974450, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 168051212 + ... + 168051221.

It is an arithmetic number, because the mean of its divisors is an integer number (504153651).

Almost surely, 2^1680512165 is an apocalyptic number.

It is an amenable number.

1680512165 is a deficient number, since it is larger than the sum of its proper divisors (336102439).

1680512165 is an equidigital number, since it uses as much as digits as its factorization.

1680512165 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 336102438.

The product of its (nonzero) digits is 14400, while the sum is 35.

The square root of 1680512165 is about 40994.0503609975. The cubic root of 1680512165 is about 1188.9051825955.

The spelling of 1680512165 in words is "one billion, six hundred eighty million, five hundred twelve thousand, one hundred sixty-five".