55405565 has 4 divisors (see below), whose sum is σ = 66486684. Its totient is φ = 44324448.

The previous prime is 55405561. The next prime is 55405607. The reversal of 55405565 is 56550455.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 18887716 + 36517849 = 4346^2 + 6043^2 .

It is a cyclic number.

It is not a de Polignac number, because 55405565 - 2² = 55405561 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (55405561) 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, 5540552 + ... + 5540561.

It is an arithmetic number, because the mean of its divisors is an integer number (16621671).

Almost surely, 2^55405565 is an apocalyptic number.

It is an amenable number.

55405565 is a deficient number, since it is larger than the sum of its proper divisors (11081119).

55405565 is a wasteful number, since it uses less digits than its factorization.

55405565 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 11081118.

The product of its (nonzero) digits is 75000, while the sum is 35.

The square root of 55405565 is about 7443.4914522689. The cubic root of 55405565 is about 381.2277120358.

The spelling of 55405565 in words is "fifty-five million, four hundred five thousand, five hundred sixty-five".