6643545579 has 24 divisors (see below), whose sum is σ = 10572282864. Its totient is φ = 3986520000.

The previous prime is 6643545547. The next prime is 6643545611. The reversal of 6643545579 is 9755453466.

6643545579 is a `hidden beast` number, since 6 + 6 + 43 + 545 + 57 + 9 = 666.

It is an interprime number because it is at equal distance from previous prime (6643545547) and next prime (6643545611).

It is not a de Polignac number, because 6643545579 - 2⁵ = 6643545547 is a prime.

It is not an unprimeable number, because it can be changed into a prime (6643545509) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 322212 + ... + 342209.

It is an arithmetic number, because the mean of its divisors is an integer number (440511786).

Almost surely, 2^6643545579 is an apocalyptic number.

6643545579 is a deficient number, since it is larger than the sum of its proper divisors (3928737285).

6643545579 is a wasteful number, since it uses less digits than its factorization.

6643545579 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 664539 (or 664536 counting only the distinct ones).

The product of its digits is 13608000, while the sum is 54.

The square root of 6643545579 is about 81507.9479498779. The cubic root of 6643545579 is about 1879.8937599350.

The spelling of 6643545579 in words is "six billion, six hundred forty-three million, five hundred forty-five thousand, five hundred seventy-nine".