6639535040 has 28 divisors (see below), whose sum is σ = 15810393576. Its totient is φ = 2655813888.

The previous prime is 6639535033. The next prime is 6639535043. The reversal of 6639535040 is 405359366.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (6639535043) 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, 10373954 + ... + 10374593.

Almost surely, 2^6639535040 is an apocalyptic number.

It is an amenable number.

6639535040 is an abundant number, since it is smaller than the sum of its proper divisors (9170858536).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

6639535040 is a wasteful number, since it uses less digits than its factorization.

6639535040 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 20748564 (or 20748554 counting only the distinct ones).

The product of its (nonzero) digits is 291600, while the sum is 41.

The square root of 6639535040 is about 81483.3421013154. The cubic root of 6639535040 is about 1879.5154024866.

The spelling of 6639535040 in words is "six billion, six hundred thirty-nine million, five hundred thirty-five thousand, forty".