11721121 has 8 divisors (see below), whose sum is σ = 12063744. Its totient is φ = 11381280.

The previous prime is 11721113. The next prime is 11721139. The reversal of 11721121 is 12112711.

11721121 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

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

It is a cyclic number.

It is not a de Polignac number, because 11721121 - 2³ = 11721113 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 11721095 and 11721104.

It is not an unprimeable number, because it can be changed into a prime (11721221) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 10240 + ... + 11326.

It is an arithmetic number, because the mean of its divisors is an integer number (1507968).

Almost surely, 2^11721121 is an apocalyptic number.

It is an amenable number.

11721121 is a deficient number, since it is larger than the sum of its proper divisors (342623).

11721121 is a wasteful number, since it uses less digits than its factorization.

11721121 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1391.

The product of its digits is 28, while the sum is 16.

The square root of 11721121 is about 3423.6122736081. The cubic root of 11721121 is about 227.1553918014.

Adding to 11721121 its reverse (12112711), we get a palindrome (23833832).

The spelling of 11721121 in words is "eleven million, seven hundred twenty-one thousand, one hundred twenty-one".