664437571133669 has 2 divisors, whose sum is σ = 664437571133670. Its totient is φ = 664437571133668.

The previous prime is 664437571133359. The next prime is 664437571133689. The reversal of 664437571133669 is 966331175734466.

It is a happy number.

664437571133669 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 497099932964644 + 167337638169025 = 22295738^2 + 12935905^2 .

It is a cyclic number.

It is not a de Polignac number, because 664437571133669 - 2³⁶ = 664368851656933 is a prime.

It is a super-2 number, since 2×664437571133669² (a number of 30 digits) contains 22 as substring.

It is a Sophie Germain prime.

It is a Curzon number.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (664437571133689) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 332218785566834 + 332218785566835.

It is an arithmetic number, because the mean of its divisors is an integer number (332218785566835).

Almost surely, 2^{664437571133669} is an apocalyptic number.

It is an amenable number.

664437571133669 is a deficient number, since it is larger than the sum of its proper divisors (1).

664437571133669 is an equidigital number, since it uses as much as digits as its factorization.

664437571133669 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 1234517760, while the sum is 71.

The spelling of 664437571133669 in words is "six hundred sixty-four trillion, four hundred thirty-seven billion, five hundred seventy-one million, one hundred thirty-three thousand, six hundred sixty-nine".