55505556 has 18 divisors (see below), whose sum is σ = 140305802. Its totient is φ = 18501840.

The previous prime is 55505539. The next prime is 55505557. The reversal of 55505556 is 65550555.

55505556 is a `hidden beast` number, since 5 + 550 + 55 + 56 = 666.

It can be written as a sum of positive squares in only one way, i.e., 38564100 + 16941456 = 6210^2 + 4116^2 .

It is a tau number, because it is divible by the number of its divisors (18).

It is a Harshad number since it is a multiple of its sum of digits (36), and also a Moran number because the ratio is a prime number: 1541821 = 55505556 / (5 + 5 + 5 + 0 + 5 + 5 + 5 + 6).

It is a nialpdrome in base 13.

It is a self number, because there is not a number n which added to its sum of digits gives 55505556.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (55505557) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 770875 + ... + 770946.

Almost surely, 2^55505556 is an apocalyptic number.

It is an amenable number.

55505556 is an abundant number, since it is smaller than the sum of its proper divisors (84800246).

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

55505556 is a wasteful number, since it uses less digits than its factorization.

55505556 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1541831 (or 1541826 counting only the distinct ones).

The product of its (nonzero) digits is 93750, while the sum is 36.

The square root of 55505556 is about 7450.2050978480. The cubic root of 55505556 is about 381.4569094197.

The spelling of 55505556 in words is "fifty-five million, five hundred five thousand, five hundred fifty-six".