55445891 has 4 divisors (see below), whose sum is σ = 58707432. Its totient is φ = 52184352.

The previous prime is 55445867. The next prime is 55445953. The reversal of 55445891 is 19854455.

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

It is a cyclic number.

It is not a de Polignac number, because 55445891 - 2¹⁰ = 55444867 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (55445821) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1630745 + ... + 1630778.

It is an arithmetic number, because the mean of its divisors is an integer number (14676858).

Almost surely, 2^55445891 is an apocalyptic number.

55445891 is a deficient number, since it is larger than the sum of its proper divisors (3261541).

55445891 is a wasteful number, since it uses less digits than its factorization.

55445891 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3261540.

The product of its digits is 144000, while the sum is 41.

The square root of 55445891 is about 7446.1997690097. The cubic root of 55445891 is about 381.3201796454.

The spelling of 55445891 in words is "fifty-five million, four hundred forty-five thousand, eight hundred ninety-one".