12721221125 has 32 divisors (see below), whose sum is σ = 16826940000. Its totient is φ = 9568665600.

The previous prime is 12721221061. The next prime is 12721221131. The reversal of 12721221125 is 52112212721.

It can be written as a sum of positive squares in 16 ways, for example, as 5183856001 + 7537365124 = 71999^2 + 86818^2 .

It is not a de Polignac number, because 12721221125 - 2⁶ = 12721221061 is a prime.

It is a super-2 number, since 2×12721221125² (a number of 21 digits) contains 22 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 12721221094 and 12721221103.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 2651729 + ... + 2656521.

It is an arithmetic number, because the mean of its divisors is an integer number (525841875).

Almost surely, 2^12721221125 is an apocalyptic number.

It is an amenable number.

12721221125 is a deficient number, since it is larger than the sum of its proper divisors (4105718875).

12721221125 is a wasteful number, since it uses less digits than its factorization.

12721221125 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 6074 (or 6064 counting only the distinct ones).

The product of its digits is 1120, while the sum is 26.

Adding to 12721221125 its reverse (52112212721), we get a palindrome (64833433846).

The spelling of 12721221125 in words is "twelve billion, seven hundred twenty-one million, two hundred twenty-one thousand, one hundred twenty-five".