55513440 has 144 divisors (see below), whose sum is σ = 199508400. Its totient is φ = 14017536.

The previous prime is 55513433. The next prime is 55513457. The reversal of 55513440 is 4431555.

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

It is a congruent number.

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, 26346 + ... + 28374.

It is an arithmetic number, because the mean of its divisors is an integer number (1385475).

Almost surely, 2^55513440 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 55513440, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (99754200).

55513440 is an abundant number, since it is smaller than the sum of its proper divisors (143994960).

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

55513440 is a wasteful number, since it uses less digits than its factorization.

55513440 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2069 (or 2058 counting only the distinct ones).

The product of its (nonzero) digits is 6000, while the sum is 27.

The square root of 55513440 is about 7450.7341920109. The cubic root of 55513440 is about 381.4749692568.

Adding to 55513440 its reverse (4431555), we get a palindrome (59944995).

The spelling of 55513440 in words is "fifty-five million, five hundred thirteen thousand, four hundred forty".