665544233 has 4 divisors (see below), whose sum is σ = 665610708. Its totient is φ = 665477760.

The previous prime is 665544227. The next prime is 665544281. The reversal of 665544233 is 332445566.

It is a happy number.

It is a semiprime because it is the product of two primes, and also a brilliant number, because the two primes have the same length, and also an emirpimes, since its reverse is a distinct semiprime: 332445566 = 2 ⋅166222783.

It can be written as a sum of positive squares in 2 ways, for example, as 571783744 + 93760489 = 23912^2 + 9683^2 .

It is a cyclic number.

It is not a de Polignac number, because 665544233 - 2¹² = 665540137 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (665544133) 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, 14816 + ... + 39377.

It is an arithmetic number, because the mean of its divisors is an integer number (166402677).

Almost surely, 2^665544233 is an apocalyptic number.

It is an amenable number.

665544233 is a deficient number, since it is larger than the sum of its proper divisors (66475).

665544233 is a wasteful number, since it uses less digits than its factorization.

665544233 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 66474.

The product of its digits is 259200, while the sum is 38.

The square root of 665544233 is about 25798.1439836280. The cubic root of 665544233 is about 873.0899212699.

Adding to 665544233 its reverse (332445566), we get a palindrome (997989799).

The spelling of 665544233 in words is "six hundred sixty-five million, five hundred forty-four thousand, two hundred thirty-three".