55521440 has 48 divisors (see below), whose sum is σ = 141264648. Its totient is φ = 20499456.

The previous prime is 55521377. The next prime is 55521443. The reversal of 55521440 is 4412555.

It can be written as a sum of positive squares in 4 ways, for example, as 14714896 + 40806544 = 3836^2 + 6388^2 .

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

It is not an unprimeable number, because it can be changed into a prime (55521443) by changing a digit.

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, 11267 + ... + 15426.

Almost surely, 2^55521440 is an apocalyptic number.

It is an amenable number.

55521440 is an abundant number, since it is smaller than the sum of its proper divisors (85743208).

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

55521440 is a wasteful number, since it uses less digits than its factorization.

55521440 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 26721 (or 26713 counting only the distinct ones).

The product of its (nonzero) digits is 4000, while the sum is 26.

The square root of 55521440 is about 7451.2710325152. The cubic root of 55521440 is about 381.4932930667.

Adding to 55521440 its reverse (4412555), we get a palindrome (59933995).

The spelling of 55521440 in words is "fifty-five million, five hundred twenty-one thousand, four hundred forty".