6639834240 has 576 divisors, whose sum is σ = 26207064000. Its totient is φ = 1544085504.

The previous prime is 6639834197. The next prime is 6639834241. The reversal of 6639834240 is 424389366.

6639834240 is a `hidden beast` number, since 6 + 639 + 8 + 3 + 4 + 2 + 4 + 0 = 666.

It is a tau number, because it is divible by the number of its divisors (576).

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

It is not an unprimeable number, because it can be changed into a prime (6639834241) by changing a digit.

It is a polite number, since it can be written in 71 ways as a sum of consecutive naturals, for example, 18495181 + ... + 18495539.

It is an arithmetic number, because the mean of its divisors is an integer number (45498375).

Almost surely, 2^6639834240 is an apocalyptic number.

6639834240 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 6639834240, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (13103532000).

6639834240 is an abundant number, since it is smaller than the sum of its proper divisors (19567229760).

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

6639834240 is a wasteful number, since it uses less digits than its factorization.

6639834240 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 429 (or 401 counting only the distinct ones).

The product of its (nonzero) digits is 746496, while the sum is 45.

The square root of 6639834240 is about 81485.1780387084. The cubic root of 6639834240 is about 1879.5436345118.

The spelling of 6639834240 in words is "six billion, six hundred thirty-nine million, eight hundred thirty-four thousand, two hundred forty".