12611821217 has 4 divisors (see below), whose sum is σ = 12736690836. Its totient is φ = 12486951600.

The previous prime is 12611821163. The next prime is 12611821237. The reversal of 12611821217 is 71212811621.

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

It can be written as a sum of positive squares in 2 ways, for example, as 5108103841 + 7503717376 = 71471^2 + 86624^2 .

It is a cyclic number.

It is not a de Polignac number, because 12611821217 - 2⁶ = 12611821153 is a prime.

It is a super-2 number, since 2×12611821217² (a number of 21 digits) contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (12611821237) 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, 62434658 + ... + 62434859.

It is an arithmetic number, because the mean of its divisors is an integer number (3184172709).

Almost surely, 2^12611821217 is an apocalyptic number.

It is an amenable number.

12611821217 is a deficient number, since it is larger than the sum of its proper divisors (124869619).

12611821217 is a wasteful number, since it uses less digits than its factorization.

12611821217 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 124869618.

The product of its digits is 2688, while the sum is 32.

The spelling of 12611821217 in words is "twelve billion, six hundred eleven million, eight hundred twenty-one thousand, two hundred seventeen".