6643478447 has 16 divisors (see below), whose sum is σ = 7027630848. Its totient is φ = 6267528960.

The previous prime is 6643478441. The next prime is 6643478453. The reversal of 6643478447 is 7448743466.

It is an interprime number because it is at equal distance from previous prime (6643478441) and next prime (6643478453).

It is a cyclic number.

It is not a de Polignac number, because 6643478447 - 2¹⁶ = 6643412911 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (6643478441) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 1282172 + ... + 1287342.

It is an arithmetic number, because the mean of its divisors is an integer number (439226928).

Almost surely, 2^6643478447 is an apocalyptic number.

6643478447 is a deficient number, since it is larger than the sum of its proper divisors (384152401).

6643478447 is a wasteful number, since it uses less digits than its factorization.

6643478447 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5950.

The product of its digits is 10838016, while the sum is 53.

The square root of 6643478447 is about 81507.5361362371. The cubic root of 6643478447 is about 1879.8874279018.

The spelling of 6643478447 in words is "six billion, six hundred forty-three million, four hundred seventy-eight thousand, four hundred forty-seven".