6639272640 has 1344 divisors, whose sum is σ = 31952793600. Its totient is φ = 1246371840.

The previous prime is 6639272623. The next prime is 6639272707. The reversal of 6639272640 is 462729366.

6639272640 is a `hidden beast` number, since 6 + 639 + 2 + 7 + 2 + 6 + 4 + 0 = 666.

It is a tau number, because it is divible by the number of its divisors (1344).

It is a Harshad number since it is a multiple of its sum of digits (45).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 191 ways as a sum of consecutive naturals, for example, 141261097 + ... + 141261143.

It is an arithmetic number, because the mean of its divisors is an integer number (23774400).

Almost surely, 2^6639272640 is an apocalyptic number.

6639272640 is a gapful number since it is divisible by the number (60) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 6639272640, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (15976396800).

6639272640 is an abundant number, since it is smaller than the sum of its proper divisors (25313520960).

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

6639272640 is a wasteful number, since it uses less digits than its factorization.

6639272640 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 115 (or 88 counting only the distinct ones).

The product of its (nonzero) digits is 653184, while the sum is 45.

The square root of 6639272640 is about 81481.7319403558. The cubic root of 6639272640 is about 1879.4906421514.

The spelling of 6639272640 in words is "six billion, six hundred thirty-nine million, two hundred seventy-two thousand, six hundred forty".