11655221 has 2 divisors, whose sum is σ = 11655222. Its totient is φ = 11655220.

The previous prime is 11655211. The next prime is 11655223. The reversal of 11655221 is 12255611.

It is a happy number.

11655221 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 8916196 + 2739025 = 2986^2 + 1655^2 .

It is a cyclic number.

It is not a de Polignac number, because 11655221 - 2⁶ = 11655157 is a prime.

Together with 11655223, it forms a pair of twin primes.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (11655223) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 5827610 + 5827611.

It is an arithmetic number, because the mean of its divisors is an integer number (5827611).

Almost surely, 2^11655221 is an apocalyptic number.

It is an amenable number.

11655221 is a deficient number, since it is larger than the sum of its proper divisors (1).

11655221 is an equidigital number, since it uses as much as digits as its factorization.

11655221 is an evil number, because the sum of its binary digits is even.

The product of its digits is 600, while the sum is 23.

The square root of 11655221 is about 3413.9743701440. The cubic root of 11655221 is about 226.7288773398.

The spelling of 11655221 in words is "eleven million, six hundred fifty-five thousand, two hundred twenty-one".