55275221 has 2 divisors, whose sum is σ = 55275222. Its totient is φ = 55275220.

The previous prime is 55275127. The next prime is 55275223. The reversal of 55275221 is 12257255.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 50566321 + 4708900 = 7111^2 + 2170^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-55275221 is a prime.

It is a super-3 number, since 3×55275221³ (a number of 24 digits) contains 333 as substring.

Together with 55275223, 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 (55275223) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 27637610 + 27637611.

It is an arithmetic number, because the mean of its divisors is an integer number (27637611).

Almost surely, 2^55275221 is an apocalyptic number.

It is an amenable number.

55275221 is a deficient number, since it is larger than the sum of its proper divisors (1).

55275221 is an equidigital number, since it uses as much as digits as its factorization.

55275221 is an evil number, because the sum of its binary digits is even.

The product of its digits is 7000, while the sum is 29.

The square root of 55275221 is about 7434.7307281434. The cubic root of 55275221 is about 380.9285257088.

The spelling of 55275221 in words is "fifty-five million, two hundred seventy-five thousand, two hundred twenty-one".