664165531 has 2 divisors, whose sum is σ = 664165532. Its totient is φ = 664165530.

The previous prime is 664165493. The next prime is 664165543. The reversal of 664165531 is 135561466.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 664165531 - 2¹⁹ = 663641243 is a prime.

It is a super-3 number, since 3×664165531³ (a number of 27 digits) contains 333 as substring. Note that it is a super-d number also for d = 2.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (664165591) 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, 332082765 + 332082766.

It is an arithmetic number, because the mean of its divisors is an integer number (332082766).

Almost surely, 2^664165531 is an apocalyptic number.

664165531 is a deficient number, since it is larger than the sum of its proper divisors (1).

664165531 is an equidigital number, since it uses as much as digits as its factorization.

664165531 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 64800, while the sum is 37.

The square root of 664165531 is about 25771.4091776139. The cubic root of 664165531 is about 872.4866240427.

The spelling of 664165531 in words is "six hundred sixty-four million, one hundred sixty-five thousand, five hundred thirty-one".