55240640 has 168 divisors, whose sum is σ = 165396672. Its totient is φ = 17418240.

The previous prime is 55240639. The next prime is 55240643. The reversal of 55240640 is 4604255.

55240640 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a Harshad number since it is a multiple of its sum of digits (26).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (55240643) 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 23 ways as a sum of consecutive naturals, for example, 203705 + ... + 203975.

It is an arithmetic number, because the mean of its divisors is an integer number (984504).

Almost surely, 2^55240640 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 55240640, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (82698336).

55240640 is an abundant number, since it is smaller than the sum of its proper divisors (110156032).

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

55240640 is a wasteful number, since it uses less digits than its factorization.

55240640 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 315 (or 298 counting only the distinct ones).

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

The square root of 55240640 is about 7432.4047252555. The cubic root of 55240640 is about 380.8490709543.

Adding to 55240640 its reverse (4604255), we get a palindrome (59844895).

The spelling of 55240640 in words is "fifty-five million, two hundred forty thousand, six hundred forty".