1665133823 has 4 divisors (see below), whose sum is σ = 1674759048. Its totient is φ = 1655508600.

The previous prime is 1665133777. The next prime is 1665133831. The reversal of 1665133823 is 3283315661.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 3283315661 = 757 ⋅4337273.

It is a cyclic number.

It is not a de Polignac number, because 1665133823 - 2⁶ = 1665133759 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1665133843) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 4812353 + ... + 4812698.

It is an arithmetic number, because the mean of its divisors is an integer number (418689762).

Almost surely, 2^1665133823 is an apocalyptic number.

1665133823 is a deficient number, since it is larger than the sum of its proper divisors (9625225).

1665133823 is an equidigital number, since it uses as much as digits as its factorization.

1665133823 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 9625224.

The product of its digits is 77760, while the sum is 38.

The square root of 1665133823 is about 40806.0513036976. The cubic root of 1665133823 is about 1185.2675125839.

The spelling of 1665133823 in words is "one billion, six hundred sixty-five million, one hundred thirty-three thousand, eight hundred twenty-three".