11228721 has 32 divisors (see below), whose sum is σ = 18413568. Its totient is φ = 5940480.

The previous prime is 11228689. The next prime is 11228743. The reversal of 11228721 is 12782211.

11228721 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is not a de Polignac number, because 11228721 - 2⁵ = 11228689 is a prime.

It is a Curzon number.

It is a junction number, because it is equal to n+sod(n) for n = 11228691 and 11228700.

It is not an unprimeable number, because it can be changed into a prime (11228521) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 25126 + ... + 25568.

It is an arithmetic number, because the mean of its divisors is an integer number (575424).

Almost surely, 2^11228721 is an apocalyptic number.

It is an amenable number.

11228721 is a deficient number, since it is larger than the sum of its proper divisors (7184847).

11228721 is a wasteful number, since it uses less digits than its factorization.

11228721 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 541.

The product of its digits is 448, while the sum is 24.

The square root of 11228721 is about 3350.9283788228. The cubic root of 11228721 is about 223.9288743676.

The spelling of 11228721 in words is "eleven million, two hundred twenty-eight thousand, seven hundred twenty-one".