666520333 has 4 divisors (see below), whose sum is σ = 667979260. Its totient is φ = 665061408.

The previous prime is 666520321. The next prime is 666520403. The reversal of 666520333 is 333025666.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 333025666 = 2 ⋅166512833.

It can be written as a sum of positive squares in 2 ways, for example, as 400080004 + 266440329 = 20002^2 + 16323^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-666520333 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 (666520433) 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, 728778 + ... + 729691.

It is an arithmetic number, because the mean of its divisors is an integer number (166994815).

Almost surely, 2^666520333 is an apocalyptic number.

It is an amenable number.

666520333 is a deficient number, since it is larger than the sum of its proper divisors (1458927).

666520333 is a wasteful number, since it uses less digits than its factorization.

666520333 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1458926.

The product of its (nonzero) digits is 58320, while the sum is 34.

The square root of 666520333 is about 25817.0550799273. The cubic root of 666520333 is about 873.5165429428.

Adding to 666520333 its reverse (333025666), we get a palindrome (999545999).

The spelling of 666520333 in words is "six hundred sixty-six million, five hundred twenty thousand, three hundred thirty-three".