13221206640 has 80 divisors (see below), whose sum is σ = 45539719200. Its totient is φ = 3525654528.

The previous prime is 13221206597. The next prime is 13221206641. The reversal of 13221206640 is 4660212231.

13221206640 is a `hidden beast` number, since 1 + 3 + 2 + 2 + 12 + 0 + 6 + 640 = 666.

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

It is a Harshad number since it is a multiple of its sum of digits (27).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (13221206641) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 3058305 + ... + 3062624.

It is an arithmetic number, because the mean of its divisors is an integer number (569246490).

Almost surely, 2^13221206640 is an apocalyptic number.

13221206640 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

13221206640 is an abundant number, since it is smaller than the sum of its proper divisors (32318512560).

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

13221206640 is a wasteful number, since it uses less digits than its factorization.

13221206640 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 6120951 (or 6120939 counting only the distinct ones).

The product of its (nonzero) digits is 3456, while the sum is 27.

Adding to 13221206640 its reverse (4660212231), we get a palindrome (17881418871).

The spelling of 13221206640 in words is "thirteen billion, two hundred twenty-one million, two hundred six thousand, six hundred forty".