664135081 has 2 divisors, whose sum is σ = 664135082. Its totient is φ = 664135080.

The previous prime is 664135033. The next prime is 664135091. The reversal of 664135081 is 180531466.

It is a happy number.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 384944400 + 279190681 = 19620^2 + 16709^2 .

It is a cyclic number.

It is not a de Polignac number, because 664135081 - 2⁷ = 664134953 is a prime.

It is a super-2 number, since 2×664135081² = 882150811629753122, which contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (664135001) 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, 332067540 + 332067541.

It is an arithmetic number, because the mean of its divisors is an integer number (332067541).

Almost surely, 2^664135081 is an apocalyptic number.

It is an amenable number.

664135081 is a deficient number, since it is larger than the sum of its proper divisors (1).

664135081 is an equidigital number, since it uses as much as digits as its factorization.

664135081 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 17280, while the sum is 34.

The square root of 664135081 is about 25770.8183998879. The cubic root of 664135081 is about 872.4732902062.

The spelling of 664135081 in words is "six hundred sixty-four million, one hundred thirty-five thousand, eighty-one".