11721761 has 4 divisors (see below), whose sum is σ = 11745300. Its totient is φ = 11698224.

The previous prime is 11721733. The next prime is 11721763. The reversal of 11721761 is 16712711.

11721761 is digitally balanced in base 3, because in such base it contains all the possibile digits an equal number of times.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 16712711 = 997 ⋅16763.

It can be written as a sum of positive squares in 2 ways, for example, as 10144225 + 1577536 = 3185^2 + 1256^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-11721761 is a prime.

It is a super-2 number, since 2×11721761² = 274799361882242, which contains 22 as substring.

It is a Duffinian number.

It is a Curzon number.

It is a self number, because there is not a number n which added to its sum of digits gives 11721761.

It is not an unprimeable number, because it can be changed into a prime (11721763) 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, 11006 + ... + 12023.

It is an arithmetic number, because the mean of its divisors is an integer number (2936325).

Almost surely, 2^11721761 is an apocalyptic number.

It is an amenable number.

11721761 is a deficient number, since it is larger than the sum of its proper divisors (23539).

11721761 is an equidigital number, since it uses as much as digits as its factorization.

11721761 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 23538.

The product of its digits is 588, while the sum is 26.

The square root of 11721761 is about 3423.7057408603. The cubic root of 11721761 is about 227.1595261274.

The spelling of 11721761 in words is "eleven million, seven hundred twenty-one thousand, seven hundred sixty-one".