13221209991 has 16 divisors (see below), whose sum is σ = 20066976000. Its totient is φ = 7664469120.

The previous prime is 13221209971. The next prime is 13221209999. The reversal of 13221209991 is 19990212231.

It is not a de Polignac number, because 13221209991 - 2¹¹ = 13221207943 is a prime.

It is a super-2 number, since 2×13221209991² (a number of 21 digits) contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (13221209999) 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, 8708866 + ... + 8710383.

It is an arithmetic number, because the mean of its divisors is an integer number (1254186000).

Almost surely, 2^13221209991 is an apocalyptic number.

13221209991 is a gapful number since it is divisible by the number (11) formed by its first and last digit.

13221209991 is a deficient number, since it is larger than the sum of its proper divisors (6845766009).

13221209991 is a wasteful number, since it uses less digits than its factorization.

13221209991 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 17419286.

The product of its (nonzero) digits is 17496, while the sum is 39.

The spelling of 13221209991 in words is "thirteen billion, two hundred twenty-one million, two hundred nine thousand, nine hundred ninety-one".