55442321 has 12 divisors (see below), whose sum is σ = 64527876. Its totient is φ = 47435520.

The previous prime is 55442311. The next prime is 55442327. The reversal of 55442321 is 12324455.

It is a happy number.

It can be written as a sum of positive squares in 2 ways, for example, as 40704400 + 14737921 = 6380^2 + 3839^2 .

It is a de Polignac number, because none of the positive numbers 2^k-55442321 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (55442327) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 11420 + ... + 15533.

It is an arithmetic number, because the mean of its divisors is an integer number (5377323).

Almost surely, 2^55442321 is an apocalyptic number.

It is an amenable number.

55442321 is a deficient number, since it is larger than the sum of its proper divisors (9085555).

55442321 is a wasteful number, since it uses less digits than its factorization.

55442321 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 26992 (or 26981 counting only the distinct ones).

The product of its digits is 4800, while the sum is 26.

The square root of 55442321 is about 7445.9600455549. The cubic root of 55442321 is about 381.3119954365.

Adding to 55442321 its reverse (12324455), we get a palindrome (67766776).

It can be divided in two parts, 554 and 42321, that added together give a cube (42875 = 35³).

The spelling of 55442321 in words is "fifty-five million, four hundred forty-two thousand, three hundred twenty-one".