13221811668 has 72 divisors (see below), whose sum is σ = 33484274208. Its totient is φ = 4058790528.

The previous prime is 13221811663. The next prime is 13221811697. The reversal of 13221811668 is 86611812231.

It is a Harshad number since it is a multiple of its sum of digits (39).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (13221811663) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 891046 + ... + 905762.

It is an arithmetic number, because the mean of its divisors is an integer number (465059364).

Almost surely, 2^13221811668 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 13221811668, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (16742137104).

13221811668 is an abundant number, since it is smaller than the sum of its proper divisors (20262462540).

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

13221811668 is a wasteful number, since it uses less digits than its factorization.

13221811668 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 15193 (or 15178 counting only the distinct ones).

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

The spelling of 13221811668 in words is "thirteen billion, two hundred twenty-one million, eight hundred eleven thousand, six hundred sixty-eight".