13221220001 has 12 divisors (see below), whose sum is σ = 14616440916. Its totient is φ = 11949796320.

The previous prime is 13221219961. The next prime is 13221220007. The reversal of 13221220001 is 10002212231.

It is a happy number.

It can be written as a sum of positive squares in 2 ways, for example, as 8915891776 + 4305328225 = 94424^2 + 65615^2 .

It is not a de Polignac number, because 13221220001 - 2¹⁰ = 13221218977 is a prime.

It is not an unprimeable number, because it can be changed into a prime (13221220007) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 294866 + ... + 336731.

It is an arithmetic number, because the mean of its divisors is an integer number (1218036743).

Almost surely, 2^13221220001 is an apocalyptic number.

13221220001 is a gapful number since it is divisible by the number (11) formed by its first and last digit.

It is an amenable number.

13221220001 is a deficient number, since it is larger than the sum of its proper divisors (1395220915).

13221220001 is a wasteful number, since it uses less digits than its factorization.

13221220001 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 631792 (or 631781 counting only the distinct ones).

The product of its (nonzero) digits is 48, while the sum is 14.

Adding to 13221220001 its reverse (10002212231), we get a palindrome (23223432232).

The spelling of 13221220001 in words is "thirteen billion, two hundred twenty-one million, two hundred twenty thousand, one".