3644208640 has 80 divisors (see below), whose sum is σ = 8794182672. Its totient is φ = 1448239104.

The previous prime is 3644208629. The next prime is 3644208647. The reversal of 3644208640 is 468024463.

It is a tau number, because it is divible by the number of its divisors (80).

It is a super-2 number, since 2×3644208640² = 26560513223701299200, which contains 22 as substring.

It is a self number, because there is not a number n which added to its sum of digits gives 3644208640.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (3644208647) by changing a digit.

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 7 ways as a sum of consecutive naturals, for example, 397387 + ... + 406453.

Almost surely, 2^3644208640 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 3644208640, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (4397091336).

3644208640 is an abundant number, since it is smaller than the sum of its proper divisors (5149974032).

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

3644208640 is an equidigital number, since it uses as much as digits as its factorization.

3644208640 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 9247 (or 9231 counting only the distinct ones).

The product of its (nonzero) digits is 110592, while the sum is 37.

The square root of 3644208640 is about 60367.2812043080. The cubic root of 3644208640 is about 1538.8669689220.

The spelling of 3644208640 in words is "three billion, six hundred forty-four million, two hundred eight thousand, six hundred forty".