55321540 has 48 divisors (see below), whose sum is σ = 123076800. Its totient is φ = 20829312.

The previous prime is 55321529. The next prime is 55321543. The reversal of 55321540 is 4512355.

It is not an unprimeable number, because it can be changed into a prime (55321543) 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, 74491 + ... + 75229.

It is an arithmetic number, because the mean of its divisors is an integer number (2564100).

Almost surely, 2^55321540 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 55321540, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (61538400).

55321540 is an abundant number, since it is smaller than the sum of its proper divisors (67755260).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

55321540 is a wasteful number, since it uses less digits than its factorization.

55321540 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 964 (or 962 counting only the distinct ones).

The product of its (nonzero) digits is 3000, while the sum is 25.

The square root of 55321540 is about 7437.8451180433. The cubic root of 55321540 is about 381.0348982806.

Adding to 55321540 its reverse (4512355), we get a palindrome (59833895).

The spelling of 55321540 in words is "fifty-five million, three hundred twenty-one thousand, five hundred forty".