55308240 has 240 divisors, whose sum is σ = 211236480. Its totient is φ = 12856320.

The previous prime is 55308233. The next prime is 55308241. The reversal of 55308240 is 4280355.

It is a tau number, because it is divible by the number of its divisors (240).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (55308241) by changing a digit.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 177685 + ... + 177995.

It is an arithmetic number, because the mean of its divisors is an integer number (880152).

Almost surely, 2^55308240 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 55308240, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (105618240).

55308240 is an abundant number, since it is smaller than the sum of its proper divisors (155928240).

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

55308240 is a wasteful number, since it uses less digits than its factorization.

55308240 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 362 (or 353 counting only the distinct ones).

The product of its (nonzero) digits is 4800, while the sum is 27.

The square root of 55308240 is about 7436.9509881402. The cubic root of 55308240 is about 381.0043606255.

Adding to 55308240 its reverse (4280355), we get a palindrome (59588595).

The spelling of 55308240 in words is "fifty-five million, three hundred eight thousand, two hundred forty".