55220321 has 16 divisors (see below), whose sum is σ = 62415360. Its totient is φ = 48498240.

The previous prime is 55220293. The next prime is 55220353. The reversal of 55220321 is 12302255.

It is a cyclic number.

It is not a de Polignac number, because 55220321 - 2¹⁴ = 55203937 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 55220293 and 55220302.

It is not an unprimeable number, because it can be changed into a prime (55220521) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 25736 + ... + 27798.

It is an arithmetic number, because the mean of its divisors is an integer number (3900960).

Almost surely, 2^55220321 is an apocalyptic number.

It is an amenable number.

55220321 is a deficient number, since it is larger than the sum of its proper divisors (7195039).

55220321 is a wasteful number, since it uses less digits than its factorization.

55220321 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2176.

The product of its (nonzero) digits is 600, while the sum is 20.

The square root of 55220321 is about 7431.0376798937. The cubic root of 55220321 is about 380.8023697015.

Adding to 55220321 its reverse (12302255), we get a palindrome (67522576).

The spelling of 55220321 in words is "fifty-five million, two hundred twenty thousand, three hundred twenty-one".