6645257959 has 4 divisors (see below), whose sum is σ = 7036155504. Its totient is φ = 6254360416.

The previous prime is 6645257953. The next prime is 6645257987. The reversal of 6645257959 is 9597525466.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 6645257959 - 2³ = 6645257951 is a prime.

It is a Smith number, since the sum of its digits (58) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (6645257951) 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 in 3 ways as a sum of consecutive naturals, for example, 195448747 + ... + 195448780.

It is an arithmetic number, because the mean of its divisors is an integer number (1759038876).

Almost surely, 2^6645257959 is an apocalyptic number.

6645257959 is a deficient number, since it is larger than the sum of its proper divisors (390897545).

6645257959 is a wasteful number, since it uses less digits than its factorization.

6645257959 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 390897544.

The product of its digits is 20412000, while the sum is 58.

The square root of 6645257959 is about 81518.4516474645. The cubic root of 6645257959 is about 1880.0552608436.

The spelling of 6645257959 in words is "six billion, six hundred forty-five million, two hundred fifty-seven thousand, nine hundred fifty-nine".