6638570640 has 480 divisors, whose sum is σ = 25114392576. Its totient is φ = 1560453120.

The previous prime is 6638570633. The next prime is 6638570651. The reversal of 6638570640 is 460758366.

6638570640 is a `hidden beast` number, since 6 + 6 + 38 + 570 + 6 + 40 = 666.

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

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 95 ways as a sum of consecutive naturals, for example, 39751837 + ... + 39752003.

Almost surely, 2^6638570640 is an apocalyptic number.

6638570640 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 6638570640, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (12557196288).

6638570640 is an abundant number, since it is smaller than the sum of its proper divisors (18475821936).

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

6638570640 is a wasteful number, since it uses less digits than its factorization.

6638570640 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 367 (or 358 counting only the distinct ones).

The product of its (nonzero) digits is 725760, while the sum is 45.

The square root of 6638570640 is about 81477.4241124497. The cubic root of 6638570640 is about 1879.4243974985.

The spelling of 6638570640 in words is "six billion, six hundred thirty-eight million, five hundred seventy thousand, six hundred forty".