55211642221 has 2 divisors, whose sum is σ = 55211642222. Its totient is φ = 55211642220.

The previous prime is 55211642219. The next prime is 55211642249. The reversal of 55211642221 is 12224611255.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 55210900900 + 741321 = 234970^2 + 861^2 .

It is a cyclic number.

It is not a de Polignac number, because 55211642221 - 2¹ = 55211642219 is a prime.

Together with 55211642219, it forms a pair of twin primes.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (55211642621) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 27605821110 + 27605821111.

It is an arithmetic number, because the mean of its divisors is an integer number (27605821111).

Almost surely, 2^55211642221 is an apocalyptic number.

It is an amenable number.

55211642221 is a deficient number, since it is larger than the sum of its proper divisors (1).

55211642221 is an equidigital number, since it uses as much as digits as its factorization.

55211642221 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 9600, while the sum is 31.

The spelling of 55211642221 in words is "fifty-five billion, two hundred eleven million, six hundred forty-two thousand, two hundred twenty-one".