55005581 has 4 divisors (see below), whose sum is σ = 57397152. Its totient is φ = 52614012.

The previous prime is 55005553. The next prime is 55005583. The reversal of 55005581 is 18550055.

55005581 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 55005581 - 2¹⁰ = 55004557 is a prime.

It is a super-2 number, since 2×55005581² = 6051227882295122, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (55005583) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1195751 + ... + 1195796.

It is an arithmetic number, because the mean of its divisors is an integer number (14349288).

Almost surely, 2^55005581 is an apocalyptic number.

It is an amenable number.

55005581 is a deficient number, since it is larger than the sum of its proper divisors (2391571).

55005581 is a wasteful number, since it uses less digits than its factorization.

55005581 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2391570.

The product of its (nonzero) digits is 5000, while the sum is 29.

The square root of 55005581 is about 7416.5747484941. The cubic root of 55005581 is about 380.3081088397.

The spelling of 55005581 in words is "fifty-five million, five thousand, five hundred eighty-one".