11721866 has 8 divisors (see below), whose sum is σ = 18935364. Its totient is φ = 5410080.

The previous prime is 11721839. The next prime is 11721869. The reversal of 11721866 is 66812711.

It is a happy number.

11721866 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It can be written as a sum of positive squares in 2 ways, for example, as 10465225 + 1256641 = 3235^2 + 1121^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (11721869) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 225395 + ... + 225446.

Almost surely, 2^11721866 is an apocalyptic number.

11721866 is a deficient number, since it is larger than the sum of its proper divisors (7213498).

11721866 is a wasteful number, since it uses less digits than its factorization.

11721866 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 450856.

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

The square root of 11721866 is about 3423.7210750877. The cubic root of 11721866 is about 227.1602044009.

The spelling of 11721866 in words is "eleven million, seven hundred twenty-one thousand, eight hundred sixty-six".