11506721 has 4 divisors (see below), whose sum is σ = 11636100. Its totient is φ = 11377344.

The previous prime is 11506709. The next prime is 11506751. The reversal of 11506721 is 12760511.

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 4558225 + 6948496 = 2135^2 + 2636^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-11506721 is a prime.

It is a super-3 number, since 3×11506721³ (a number of 22 digits) contains 333 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (11506751) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 64556 + ... + 64733.

It is an arithmetic number, because the mean of its divisors is an integer number (2909025).

Almost surely, 2^11506721 is an apocalyptic number.

It is an amenable number.

11506721 is a deficient number, since it is larger than the sum of its proper divisors (129379).

11506721 is an equidigital number, since it uses as much as digits as its factorization.

11506721 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 129378.

The product of its (nonzero) digits is 420, while the sum is 23.

The square root of 11506721 is about 3392.1558042048. The cubic root of 11506721 is about 225.7618356686.

The spelling of 11506721 in words is "eleven million, five hundred six thousand, seven hundred twenty-one".