646533331 has 2 divisors, whose sum is σ = 646533332. Its totient is φ = 646533330.

The previous prime is 646533323. The next prime is 646533353. The reversal of 646533331 is 133335646.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 646533331 - 2³ = 646533323 is a prime.

It is a super-2 number, since 2×646533331² = 836010696187911122, which contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (646533361) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 323266665 + 323266666.

It is an arithmetic number, because the mean of its divisors is an integer number (323266666).

Almost surely, 2^646533331 is an apocalyptic number.

646533331 is a deficient number, since it is larger than the sum of its proper divisors (1).

646533331 is an equidigital number, since it uses as much as digits as its factorization.

646533331 is an odious number, because the sum of its binary digits is odd.

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

The square root of 646533331 is about 25427.0197034572. The cubic root of 646533331 is about 864.6963777848.

Adding to 646533331 its reverse (133335646), we get a palindrome (779868977).

The spelling of 646533331 in words is "six hundred forty-six million, five hundred thirty-three thousand, three hundred thirty-one".