664216433 has 4 divisors (see below), whose sum is σ = 664286628. Its totient is φ = 664146240.

The previous prime is 664216417. The next prime is 664216439. The reversal of 664216433 is 334612466.

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.

It can be written as a sum of positive squares in 2 ways, for example, as 170354704 + 493861729 = 13052^2 + 22223^2 .

It is a cyclic number.

It is not a de Polignac number, because 664216433 - 2⁴ = 664216417 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 664216393 and 664216402.

It is not an unprimeable number, because it can be changed into a prime (664216439) 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, 18188 + ... + 40733.

It is an arithmetic number, because the mean of its divisors is an integer number (166071657).

Almost surely, 2^664216433 is an apocalyptic number.

It is an amenable number.

664216433 is a deficient number, since it is larger than the sum of its proper divisors (70195).

664216433 is a wasteful number, since it uses less digits than its factorization.

664216433 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 70194.

The product of its digits is 62208, while the sum is 35.

The square root of 664216433 is about 25772.3967259547. The cubic root of 664216433 is about 872.5089127531.

Adding to 664216433 its reverse (334612466), we get a palindrome (998828899).

The spelling of 664216433 in words is "six hundred sixty-four million, two hundred sixteen thousand, four hundred thirty-three".