55002221 has 2 divisors, whose sum is σ = 55002222. Its totient is φ = 55002220.

The previous prime is 55002179. The next prime is 55002229. The reversal of 55002221 is 12220055.

55002221 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., 52722121 + 2280100 = 7261^2 + 1510^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-55002221 is a prime.

It is a Chen prime.

It is a self number, because there is not a number n which added to its sum of digits gives 55002221.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (55002229) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 27501110 + 27501111.

It is an arithmetic number, because the mean of its divisors is an integer number (27501111).

Almost surely, 2^55002221 is an apocalyptic number.

It is an amenable number.

55002221 is a deficient number, since it is larger than the sum of its proper divisors (1).

55002221 is an equidigital number, since it uses as much as digits as its factorization.

55002221 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 200, while the sum is 17.

The square root of 55002221 is about 7416.3482253735. The cubic root of 55002221 is about 380.3003650117.

Adding to 55002221 its reverse (12220055), we get a palindrome (67222276).

The spelling of 55002221 in words is "fifty-five million, two thousand, two hundred twenty-one".