55511440 has 40 divisors (see below), whose sum is σ = 129958200. Its totient is φ = 22050816.

The previous prime is 55511437. The next prime is 55511459. The reversal of 55511440 is 4411555.

It is a happy number.

It can be written as a sum of positive squares in 4 ways, for example, as 692224 + 54819216 = 832^2 + 7404^2 .

It is a tau number, because it is divible by the number of its divisors (40).

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 7 ways as a sum of consecutive naturals, for example, 9592 + ... + 14248.

It is an arithmetic number, because the mean of its divisors is an integer number (3248955).

Almost surely, 2^55511440 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 55511440, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (64979100).

55511440 is an abundant number, since it is smaller than the sum of its proper divisors (74446760).

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

55511440 is a wasteful number, since it uses less digits than its factorization.

55511440 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4819 (or 4813 counting only the distinct ones).

The product of its (nonzero) digits is 2000, while the sum is 25.

The square root of 55511440 is about 7450.5999758409. The cubic root of 55511440 is about 381.4703880292.

Adding to 55511440 its reverse (4411555), we get a palindrome (59922995).

The spelling of 55511440 in words is "fifty-five million, five hundred eleven thousand, four hundred forty".