1665798005 has 8 divisors (see below), whose sum is σ = 1999185624. Its totient is φ = 1332486400.

The previous prime is 1665797999. The next prime is 1665798031. The reversal of 1665798005 is 5008975661.

It can be written as a sum of positive squares in 4 ways, for example, as 323748049 + 1342049956 = 17993^2 + 36634^2 .

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

It is not a de Polignac number, because 1665798005 - 2¹⁰ = 1665796981 is a prime.

It is a Duffinian number.

It is a congruent 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, 56465 + ... + 80745.

It is an arithmetic number, because the mean of its divisors is an integer number (249898203).

Almost surely, 2^1665798005 is an apocalyptic number.

It is an amenable number.

1665798005 is a deficient number, since it is larger than the sum of its proper divisors (333387619).

1665798005 is a wasteful number, since it uses less digits than its factorization.

1665798005 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 38007.

The product of its (nonzero) digits is 453600, while the sum is 47.

The square root of 1665798005 is about 40814.1887705734. The cubic root of 1665798005 is about 1185.4250832428.

The spelling of 1665798005 in words is "one billion, six hundred sixty-five million, seven hundred ninety-eight thousand, five".