3681221113821 has 32 divisors (see below), whose sum is σ = 4981617780480. Its totient is φ = 2417758834176.

The previous prime is 3681221113799. The next prime is 3681221113847. The reversal of 3681221113821 is 1283111221863.

It is not a de Polignac number, because 3681221113821 - 2¹⁹ = 3681220589533 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 3681221113821.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (3681221113321) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 106725040 + ... + 106759526.

It is an arithmetic number, because the mean of its divisors is an integer number (155675555640).

Almost surely, 2^{3681221113821} is an apocalyptic number.

It is an amenable number.

3681221113821 is a deficient number, since it is larger than the sum of its proper divisors (1300396666659).

3681221113821 is a wasteful number, since it uses less digits than its factorization.

3681221113821 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 36453.

The product of its digits is 27648, while the sum is 39.

The spelling of 3681221113821 in words is "three trillion, six hundred eighty-one billion, two hundred twenty-one million, one hundred thirteen thousand, eight hundred twenty-one".