3644621568 has 540 divisors, whose sum is σ = 13448984472. Its totient is φ = 975421440.

The previous prime is 3644621567. The next prime is 3644621581. The reversal of 3644621568 is 8651264463.

3644621568 is a `hidden beast` number, since 3 + 64 + 4 + 6 + 21 + 568 = 666.

Its product of digits (829440) is a multiple of the sum of its prime divisors (240).

It is not an unprimeable number, because it can be changed into a prime (3644621567) by changing a digit.

It is a polite number, since it can be written in 59 ways as a sum of consecutive naturals, for example, 17272983 + ... + 17273193.

Almost surely, 2^3644621568 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 3644621568, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (6724492236).

3644621568 is an abundant number, since it is smaller than the sum of its proper divisors (9804362904).

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

3644621568 is a wasteful number, since it uses less digits than its factorization.

3644621568 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 270 (or 240 counting only the distinct ones).

The product of its digits is 829440, while the sum is 45.

The square root of 3644621568 is about 60370.7012382662. The cubic root of 3644621568 is about 1538.9250901149.

The spelling of 3644621568 in words is "three billion, six hundred forty-four million, six hundred twenty-one thousand, five hundred sixty-eight".