55433221 has 2 divisors, whose sum is σ = 55433222. Its totient is φ = 55433220.

The previous prime is 55433171. The next prime is 55433227. The reversal of 55433221 is 12233455.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 44076321 + 11356900 = 6639^2 + 3370^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-55433221 is a prime.

It is a nialpdrome in base 10.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (55433227) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 27716610 + 27716611.

It is an arithmetic number, because the mean of its divisors is an integer number (27716611).

Almost surely, 2^55433221 is an apocalyptic number.

It is an amenable number.

55433221 is a deficient number, since it is larger than the sum of its proper divisors (1).

55433221 is an equidigital number, since it uses as much as digits as its factorization.

55433221 is an evil number, because the sum of its binary digits is even.

The product of its digits is 3600, while the sum is 25.

The square root of 55433221 is about 7445.3489508552. The cubic root of 55433221 is about 381.2911321384.

Adding to 55433221 its reverse (12233455), we get a palindrome (67666676).

The spelling of 55433221 in words is "fifty-five million, four hundred thirty-three thousand, two hundred twenty-one".