55505561 has 8 divisors (see below), whose sum is σ = 60138144. Its totient is φ = 51024960.

The previous prime is 55505557. The next prime is 55505581. The reversal of 55505561 is 16550555.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 55505561 - 2² = 55505557 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (55505521) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 37235 + ... + 38696.

It is an arithmetic number, because the mean of its divisors is an integer number (7517268).

Almost surely, 2^55505561 is an apocalyptic number.

It is an amenable number.

55505561 is a deficient number, since it is larger than the sum of its proper divisors (4632583).

55505561 is a wasteful number, since it uses less digits than its factorization.

55505561 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 75991.

The product of its (nonzero) digits is 18750, while the sum is 32.

The square root of 55505561 is about 7450.2054334092. The cubic root of 55505561 is about 381.4569208737.

It can be divided in two parts, 5550 and 5561, that added together give a palindrome (11111).

The spelling of 55505561 in words is "fifty-five million, five hundred five thousand, five hundred sixty-one".