1664105593 has 4 divisors (see below), whose sum is σ = 1680581988. Its totient is φ = 1647629200.

The previous prime is 1664105567. The next prime is 1664105609. The reversal of 1664105593 is 3955014661.

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 1490577664 + 173527929 = 38608^2 + 13173^2 .

It is a cyclic number.

It is not a de Polignac number, because 1664105593 - 2²⁵ = 1630551161 is a prime.

It is a Smith number, since the sum of its digits (40) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (1664105563) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 8238046 + ... + 8238247.

It is an arithmetic number, because the mean of its divisors is an integer number (420145497).

Almost surely, 2^1664105593 is an apocalyptic number.

It is an amenable number.

1664105593 is a deficient number, since it is larger than the sum of its proper divisors (16476395).

1664105593 is a wasteful number, since it uses less digits than its factorization.

1664105593 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 16476394.

The product of its (nonzero) digits is 97200, while the sum is 40.

The square root of 1664105593 is about 40793.4503689011. The cubic root of 1664105593 is about 1185.0234924455.

The spelling of 1664105593 in words is "one billion, six hundred sixty-four million, one hundred five thousand, five hundred ninety-three".