13221207651 has 4 divisors (see below), whose sum is σ = 17628276872. Its totient is φ = 8814138432.

The previous prime is 13221207631. The next prime is 13221207689. The reversal of 13221207651 is 15670212231.

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

It is not a de Polignac number, because 13221207651 - 2⁷ = 13221207523 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (13221207611) 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, 2203534606 + ... + 2203534611.

It is an arithmetic number, because the mean of its divisors is an integer number (4407069218).

Almost surely, 2^13221207651 is an apocalyptic number.

13221207651 is a deficient number, since it is larger than the sum of its proper divisors (4407069221).

13221207651 is an equidigital number, since it uses as much as digits as its factorization.

13221207651 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4407069220.

The product of its (nonzero) digits is 5040, while the sum is 30.

Adding to 13221207651 its reverse (15670212231), we get a palindrome (28891419882).

The spelling of 13221207651 in words is "thirteen billion, two hundred twenty-one million, two hundred seven thousand, six hundred fifty-one".