664235531 has 2 divisors, whose sum is σ = 664235532. Its totient is φ = 664235530.

The previous prime is 664235503. The next prime is 664235587. The reversal of 664235531 is 135532466.

It is a weak prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-664235531 is a prime.

It is a super-2 number, since 2×664235531² = 882417681285703922, which contains 22 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 664235491 and 664235500.

It is not a weakly prime, because it can be changed into another prime (664235501) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 332117765 + 332117766.

It is an arithmetic number, because the mean of its divisors is an integer number (332117766).

Almost surely, 2^664235531 is an apocalyptic number.

664235531 is a deficient number, since it is larger than the sum of its proper divisors (1).

664235531 is an equidigital number, since it uses as much as digits as its factorization.

664235531 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 64800, while the sum is 35.

The square root of 664235531 is about 25772.7672359799. The cubic root of 664235531 is about 872.5172749951.

Adding to 664235531 its reverse (135532466), we get a palindrome (799767997).

The spelling of 664235531 in words is "six hundred sixty-four million, two hundred thirty-five thousand, five hundred thirty-one".