55306321 has 32 divisors (see below), whose sum is σ = 71781120. Its totient is φ = 41472000.

The previous prime is 55306319. The next prime is 55306327. The reversal of 55306321 is 12360355.

It is a happy number.

55306321 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a 4-Lehmer number, since φ(55306321) divides (55306321-1)⁴.

It is a cyclic number.

It is not a de Polignac number, because 55306321 - 2¹ = 55306319 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (55306327) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 137721 + ... + 138121.

It is an arithmetic number, because the mean of its divisors is an integer number (2243160).

Almost surely, 2^55306321 is an apocalyptic number.

It is an amenable number.

55306321 is a deficient number, since it is larger than the sum of its proper divisors (16474799).

55306321 is a wasteful number, since it uses less digits than its factorization.

55306321 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 505.

The product of its (nonzero) digits is 2700, while the sum is 25.

The square root of 55306321 is about 7436.8219690941. The cubic root of 55306321 is about 380.9999540740. Note that the first 4 decimals are identical.

Adding to 55306321 its reverse (12360355), we get a palindrome (67666676).

The spelling of 55306321 in words is "fifty-five million, three hundred six thousand, three hundred twenty-one".