55221317887 has 4 divisors (see below), whose sum is σ = 56713785976. Its totient is φ = 53728849800.

The previous prime is 55221317873. The next prime is 55221317891. The reversal of 55221317887 is 78871312255.

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 55221317887 - 2¹⁹ = 55220793599 is a prime.

It is a super-2 number, since 2×55221317887² (a number of 22 digits) contains 22 as substring.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 55221317887.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (55221317807) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 746233989 + ... + 746234062.

It is an arithmetic number, because the mean of its divisors is an integer number (14178446494).

Almost surely, 2^55221317887 is an apocalyptic number.

55221317887 is a deficient number, since it is larger than the sum of its proper divisors (1492468089).

55221317887 is a wasteful number, since it uses less digits than its factorization.

55221317887 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1492468088.

The product of its digits is 940800, while the sum is 49.

The spelling of 55221317887 in words is "fifty-five billion, two hundred twenty-one million, three hundred seventeen thousand, eight hundred eighty-seven".