55481681 has 4 divisors (see below), whose sum is σ = 57893952. Its totient is φ = 53069412.

The previous prime is 55481677. The next prime is 55481687. The reversal of 55481681 is 18618455.

55481681 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 55481681 - 2² = 55481677 is a prime.

It is a super-2 number, since 2×55481681² = 6156433853171522, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (55481687) 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, 1206101 + ... + 1206146.

It is an arithmetic number, because the mean of its divisors is an integer number (14473488).

Almost surely, 2^55481681 is an apocalyptic number.

It is an amenable number.

55481681 is a deficient number, since it is larger than the sum of its proper divisors (2412271).

55481681 is a wasteful number, since it uses less digits than its factorization.

55481681 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2412270.

The product of its digits is 38400, while the sum is 38.

The square root of 55481681 is about 7448.6026206262. The cubic root of 55481681 is about 381.4022086506.

The spelling of 55481681 in words is "fifty-five million, four hundred eighty-one thousand, six hundred eighty-one".