1665685393 has 8 divisors (see below), whose sum is σ = 1706976936. Its totient is φ = 1624425600.

The previous prime is 1665685361. The next prime is 1665685403. The reversal of 1665685393 is 3935865661.

It can be written as a sum of positive squares in 4 ways, for example, as 75829264 + 1589856129 = 8708^2 + 39873^2 .

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

It is a cyclic number.

It is not a de Polignac number, because 1665685393 - 2⁵ = 1665685361 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 1665685393.

It is not an unprimeable number, because it can be changed into a prime (1665685493) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 125755 + ... + 138367.

It is an arithmetic number, because the mean of its divisors is an integer number (213372117).

Almost surely, 2^1665685393 is an apocalyptic number.

It is an amenable number.

1665685393 is a deficient number, since it is larger than the sum of its proper divisors (41291543).

1665685393 is a wasteful number, since it uses less digits than its factorization.

1665685393 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 15875.

The product of its digits is 3499200, while the sum is 52.

The square root of 1665685393 is about 40812.8091780019. The cubic root of 1665685393 is about 1185.3983701004.

The spelling of 1665685393 in words is "one billion, six hundred sixty-five million, six hundred eighty-five thousand, three hundred ninety-three".