1801680665 has 8 divisors (see below), whose sum is σ = 2162290248. Its totient is φ = 1441162240.

The previous prime is 1801680649. The next prime is 1801680677. The reversal of 1801680665 is 5660861081.

It is a happy number.

It can be written as a sum of positive squares in 4 ways, for example, as 794506969 + 1007173696 = 28187^2 + 31736^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 1801680665 - 2⁴ = 1801680649 is a prime.

It is a Duffinian number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 33209 + ... + 68601.

It is an arithmetic number, because the mean of its divisors is an integer number (270286281).

Almost surely, 2^1801680665 is an apocalyptic number.

It is an amenable number.

1801680665 is a deficient number, since it is larger than the sum of its proper divisors (360609583).

1801680665 is a wasteful number, since it uses less digits than its factorization.

1801680665 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 45579.

The product of its (nonzero) digits is 69120, while the sum is 41.

The square root of 1801680665 is about 42446.2090769011. The cubic root of 1801680665 is about 1216.8188792697.

The spelling of 1801680665 in words is "one billion, eight hundred one million, six hundred eighty thousand, six hundred sixty-five".