55661143 has 4 divisors (see below), whose sum is σ = 55709848. Its totient is φ = 55612440.

The previous prime is 55661129. The next prime is 55661147. The reversal of 55661143 is 34116655.

55661143 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.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-55661143 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (55661147) 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, 22596 + ... + 24937.

It is an arithmetic number, because the mean of its divisors is an integer number (13927462).

Almost surely, 2^55661143 is an apocalyptic number.

55661143 is a deficient number, since it is larger than the sum of its proper divisors (48705).

55661143 is a wasteful number, since it uses less digits than its factorization.

55661143 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 48704.

The product of its digits is 10800, while the sum is 31.

The square root of 55661143 is about 7460.6395838427. The cubic root of 55661143 is about 381.8129961039.

Adding to 55661143 its reverse (34116655), we get a palindrome (89777798).

The spelling of 55661143 in words is "fifty-five million, six hundred sixty-one thousand, one hundred forty-three".