11686721 has 6 divisors (see below), whose sum is σ = 12076866. Its totient is φ = 11308800.

The previous prime is 11686711. The next prime is 11686723. The reversal of 11686721 is 12768611.

It is a happy number.

It can be written as a sum of positive squares in only one way, i.e., 8673025 + 3013696 = 2945^2 + 1736^2 .

It is not a de Polignac number, because 11686721 - 2¹⁸ = 11424577 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (11686723) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 5120 + ... + 7041.

It is an arithmetic number, because the mean of its divisors is an integer number (2012811).

Almost surely, 2^11686721 is an apocalyptic number.

It is an amenable number.

11686721 is a deficient number, since it is larger than the sum of its proper divisors (390145).

11686721 is an equidigital number, since it uses as much as digits as its factorization.

11686721 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 12223 (or 12192 counting only the distinct ones).

The product of its digits is 4032, while the sum is 32.

The square root of 11686721 is about 3418.5846486521. The cubic root of 11686721 is about 226.9329499811.

The spelling of 11686721 in words is "eleven million, six hundred eighty-six thousand, seven hundred twenty-one".