1660686665 has 8 divisors (see below), whose sum is σ = 2173989888. Its totient is φ = 1207772080.

The previous prime is 1660686649. The next prime is 1660686679. The reversal of 1660686665 is 5666860661.

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

It is not a de Polignac number, because 1660686665 - 2⁴ = 1660686649 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, 15097097 + ... + 15097206.

It is an arithmetic number, because the mean of its divisors is an integer number (271748736).

Almost surely, 2^1660686665 is an apocalyptic number.

It is an amenable number.

1660686665 is a deficient number, since it is larger than the sum of its proper divisors (513303223).

1660686665 is a wasteful number, since it uses less digits than its factorization.

1660686665 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 30194319.

The product of its (nonzero) digits is 1866240, while the sum is 50.

The square root of 1660686665 is about 40751.5234684545. The cubic root of 1660686665 is about 1184.2113869687.

The spelling of 1660686665 in words is "one billion, six hundred sixty million, six hundred eighty-six thousand, six hundred sixty-five".