11751721 has 4 divisors (see below), whose sum is σ = 11893392. Its totient is φ = 11610052.

The previous prime is 11751713. The next prime is 11751731. The reversal of 11751721 is 12715711.

11751721 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 a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 11751721 - 2³ = 11751713 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (11751731) 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, 70711 + ... + 70876.

It is an arithmetic number, because the mean of its divisors is an integer number (2973348).

Almost surely, 2^11751721 is an apocalyptic number.

It is an amenable number.

11751721 is a deficient number, since it is larger than the sum of its proper divisors (141671).

11751721 is an equidigital number, since it uses as much as digits as its factorization.

11751721 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 141670.

The product of its digits is 490, while the sum is 25.

The square root of 11751721 is about 3428.0783246595. The cubic root of 11751721 is about 227.3528960862.

The spelling of 11751721 in words is "eleven million, seven hundred fifty-one thousand, seven hundred twenty-one".