11506721217 has 16 divisors (see below), whose sum is σ = 15746635968. Its totient is φ = 7469694720.

The previous prime is 11506721189. The next prime is 11506721231. The reversal of 11506721217 is 71212760511.

11506721217 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is not a de Polignac number, because 11506721217 - 2¹⁰ = 11506720193 is a prime.

It is a super-2 number, since 2×11506721217² (a number of 21 digits) contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (11506721417) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 25108 + ... + 153765.

It is an arithmetic number, because the mean of its divisors is an integer number (984164748).

Almost surely, 2^11506721217 is an apocalyptic number.

It is an amenable number.

11506721217 is a deficient number, since it is larger than the sum of its proper divisors (4239914751).

11506721217 is a wasteful number, since it uses less digits than its factorization.

11506721217 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 179440.

The product of its (nonzero) digits is 5880, while the sum is 33.

The spelling of 11506721217 in words is "eleven billion, five hundred six million, seven hundred twenty-one thousand, two hundred seventeen".