13212120221 has 8 divisors (see below), whose sum is σ = 13362959160. Its totient is φ = 13061334528.

The previous prime is 13212120169. The next prime is 13212120223. The reversal of 13212120221 is 12202121231.

It can be written as a sum of positive squares in 4 ways, for example, as 303979225 + 12908140996 = 17435^2 + 113614^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 13212120221 - 2²² = 13207925917 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 13212120221.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (13212120223) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 704255 + ... + 722771.

It is an arithmetic number, because the mean of its divisors is an integer number (1670369895).

Almost surely, 2^13212120221 is an apocalyptic number.

It is an amenable number.

13212120221 is a deficient number, since it is larger than the sum of its proper divisors (150838939).

13212120221 is an equidigital number, since it uses as much as digits as its factorization.

13212120221 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 26623.

The product of its (nonzero) digits is 96, while the sum is 17.

Adding to 13212120221 its reverse (12202121231), we get a palindrome (25414241452).

The spelling of 13212120221 in words is "thirteen billion, two hundred twelve million, one hundred twenty thousand, two hundred twenty-one".