55561689 has 12 divisors (see below), whose sum is σ = 81387072. Its totient is φ = 36519000.

The previous prime is 55561669. The next prime is 55561691. The reversal of 55561689 is 98616555.

It is a happy number.

55561689 is a `hidden beast` number, since 5 + 5 + 561 + 6 + 89 = 666.

It is not a de Polignac number, because 55561689 - 2¹¹ = 55559641 is a prime.

It is not an unprimeable number, because it can be changed into a prime (55561609) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 42837 + ... + 44114.

It is an arithmetic number, because the mean of its divisors is an integer number (6782256).

Almost surely, 2^55561689 is an apocalyptic number.

It is an amenable number.

55561689 is a deficient number, since it is larger than the sum of its proper divisors (25825383).

55561689 is a wasteful number, since it uses less digits than its factorization.

55561689 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 87028 (or 87025 counting only the distinct ones).

The product of its digits is 324000, while the sum is 45.

The square root of 55561689 is about 7453.9713576053. The cubic root of 55561689 is about 381.5854557501.

The spelling of 55561689 in words is "fifty-five million, five hundred sixty-one thousand, six hundred eighty-nine".