3638781680 has 20 divisors (see below), whose sum is σ = 8460167592. Its totient is φ = 1455512640.

The previous prime is 3638781667. The next prime is 3638781739. The reversal of 3638781680 is 861878363.

It is a tau number, because it is divible by the number of its divisors (20).

It is a super-2 number, since 2×3638781680² = 26481464229407244800, which contains 22 as substring.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 22742306 + ... + 22742465.

Almost surely, 2^3638781680 is an apocalyptic number.

It is an amenable number.

3638781680 is an abundant number, since it is smaller than the sum of its proper divisors (4821385912).

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

3638781680 is a wasteful number, since it uses less digits than its factorization.

3638781680 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 45484784 (or 45484778 counting only the distinct ones).

The product of its (nonzero) digits is 1161216, while the sum is 50.

The square root of 3638781680 is about 60322.3149423163. The cubic root of 3638781680 is about 1538.1026952147.

The spelling of 3638781680 in words is "three billion, six hundred thirty-eight million, seven hundred eighty-one thousand, six hundred eighty".