6638624568 has 80 divisors (see below), whose sum is σ = 18667115280. Its totient is φ = 2204209152.

The previous prime is 6638624563. The next prime is 6638624609. The reversal of 6638624568 is 8654268366.

It is a happy number.

6638624568 is a `hidden beast` number, since 6 + 6 + 3 + 8 + 624 + 5 + 6 + 8 = 666.

It is a Harshad number since it is a multiple of its sum of digits (54).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (6638624563) by changing a digit.

It is a polite number, since it can be written in 19 ways as a sum of consecutive naturals, for example, 146605 + ... + 186467.

It is an arithmetic number, because the mean of its divisors is an integer number (233338941).

Almost surely, 2^6638624568 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 6638624568, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (9333557640).

6638624568 is an abundant number, since it is smaller than the sum of its proper divisors (12028490712).

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

6638624568 is a wasteful number, since it uses less digits than its factorization.

6638624568 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 40138 (or 40125 counting only the distinct ones).

The product of its digits is 9953280, while the sum is 54.

The square root of 6638624568 is about 81477.7550500749. The cubic root of 6638624568 is about 1879.4294866123.

The spelling of 6638624568 in words is "six billion, six hundred thirty-eight million, six hundred twenty-four thousand, five hundred sixty-eight".