55988640 has 144 divisors (see below), whose sum is σ = 194594400. Its totient is φ = 14654976.

The previous prime is 55988627. The next prime is 55988651. The reversal of 55988640 is 4688955.

It is a tau number, because it is divible by the number of its divisors (144).

It is a Harshad number since it is a multiple of its sum of digits (45).

It is an unprimeable number.

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 23 ways as a sum of consecutive naturals, for example, 84631 + ... + 85289.

It is an arithmetic number, because the mean of its divisors is an integer number (1351350).

Almost surely, 2^55988640 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 55988640, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (97297200).

55988640 is an abundant number, since it is smaller than the sum of its proper divisors (138605760).

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

55988640 is a wasteful number, since it uses less digits than its factorization.

55988640 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 739 (or 728 counting only the distinct ones).

The product of its (nonzero) digits is 345600, while the sum is 45.

The square root of 55988640 is about 7482.5557131237. Note that the first 3 decimals coincide. The cubic root of 55988640 is about 382.5603646880.

The spelling of 55988640 in words is "fifty-five million, nine hundred eighty-eight thousand, six hundred forty".