55168551721 has 4 divisors (see below), whose sum is σ = 55704168832. Its totient is φ = 54632934612.

The previous prime is 55168551667. The next prime is 55168551749. The reversal of 55168551721 is 12715586155.

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 55168551721 - 2⁷ = 55168551593 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (55168551751) 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 3 ways as a sum of consecutive naturals, for example, 267808401 + ... + 267808606.

It is an arithmetic number, because the mean of its divisors is an integer number (13926042208).

Almost surely, 2^55168551721 is an apocalyptic number.

It is an amenable number.

55168551721 is a deficient number, since it is larger than the sum of its proper divisors (535617111).

55168551721 is a wasteful number, since it uses less digits than its factorization.

55168551721 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 535617110.

The product of its digits is 420000, while the sum is 46.

The spelling of 55168551721 in words is "fifty-five billion, one hundred sixty-eight million, five hundred fifty-one thousand, seven hundred twenty-one".