3844638411221 has 4 divisors (see below), whose sum is σ = 3844938294444. Its totient is φ = 3844338528000.

The previous prime is 3844638411209. The next prime is 3844638411223. The reversal of 3844638411221 is 1221148364483.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 2068045324900 + 1776593086321 = 1438070^2 + 1332889^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-3844638411221 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (3844638411223) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 149922380 + ... + 149948021.

It is an arithmetic number, because the mean of its divisors is an integer number (961234573611).

Almost surely, 2^{3844638411221} is an apocalyptic number.

It is an amenable number.

3844638411221 is a deficient number, since it is larger than the sum of its proper divisors (299883223).

3844638411221 is a wasteful number, since it uses less digits than its factorization.

3844638411221 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 299883222.

The product of its digits is 884736, while the sum is 47.

The spelling of 3844638411221 in words is "three trillion, eight hundred forty-four billion, six hundred thirty-eight million, four hundred eleven thousand, two hundred twenty-one".