55805440 has 40 divisors (see below), whose sum is σ = 133808400. Its totient is φ = 22321152.

The previous prime is 55805419. The next prime is 55805447. The reversal of 55805440 is 4450855.

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

It is a super-2 number, since 2×55805440² = 6228494267187200, which contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (55805447) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 8340 + ... + 13459.

It is an arithmetic number, because the mean of its divisors is an integer number (3345210).

Almost surely, 2^55805440 is an apocalyptic number.

It is an amenable number.

55805440 is an abundant number, since it is smaller than the sum of its proper divisors (78002960).

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

55805440 is an equidigital number, since it uses as much as digits as its factorization.

55805440 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 21822 (or 21806 counting only the distinct ones).

The product of its (nonzero) digits is 16000, while the sum is 31.

The square root of 55805440 is about 7470.3038760147. The cubic root of 55805440 is about 382.1426511443.

The spelling of 55805440 in words is "fifty-five million, eight hundred five thousand, four hundred forty".