550566221 has 2 divisors, whose sum is σ = 550566222. Its totient is φ = 550566220.

The previous prime is 550566197. The next prime is 550566223. The reversal of 550566221 is 122665055.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 427910596 + 122655625 = 20686^2 + 11075^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-550566221 is a prime.

It is a Sophie Germain prime.

Together with 550566223, it forms a pair of twin primes.

It is a Chen prime.

It is a Curzon number.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (550566223) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 275283110 + 275283111.

It is an arithmetic number, because the mean of its divisors is an integer number (275283111).

Almost surely, 2^550566221 is an apocalyptic number.

It is an amenable number.

550566221 is a deficient number, since it is larger than the sum of its proper divisors (1).

550566221 is an equidigital number, since it uses as much as digits as its factorization.

550566221 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 18000, while the sum is 32.

The square root of 550566221 is about 23464.1475660208. The cubic root of 550566221 is about 819.6023359343.

The spelling of 550566221 in words is "five hundred fifty million, five hundred sixty-six thousand, two hundred twenty-one".