664043541 has 16 divisors (see below), whose sum is σ = 1032528000.
Its totient is φ = 379452864.
The previous prime is 664043533. The next prime is 664043543. The reversal of 664043541 is 145340466.
It is not a de Polignac number, because 664043541 - 23 = 664043533 is a prime.
It is a Curzon number.
It is a congruent number.
It is not an unprimeable number, because it can be changed into a prime (664043543) by changing a digit.
It is a pernicious number, because its binary representation contains a prime number (11) of ones.
It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 321636 + ... + 323693.
It is an arithmetic number, because the mean of its divisors is an integer number (64533000).
Almost surely, 2664043541 is an apocalyptic number.
It is an amenable number.
664043541 is a deficient number, since it is larger than the sum of its proper divisors (368484459).
664043541 is an equidigital number, since it uses as much as digits as its factorization.
664043541 is an odious number, because the sum of its binary digits is odd.
The sum of its prime factors is 645353 (or 645339 counting only the distinct ones).
The product of its (nonzero) digits is 34560, while the sum is 33.
The square root of 664043541 is about 25769.0422988515.
The cubic root of 664043541 is about 872.4332030428.
The spelling of 664043541 in words is "six hundred sixty-four million, forty-three thousand, five hundred forty-one".