21216472855 has 16 divisors (see below), whose sum is σ = 26978948640. Its totient is φ = 15961987072.

The previous prime is 21216472829. The next prime is 21216472903. The reversal of 21216472855 is 55827461212.

It is a de Polignac number, because none of the positive numbers 2^k-21216472855 is a prime.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 7887 + ... + 206143.

It is an arithmetic number, because the mean of its divisors is an integer number (1686184290).

Almost surely, 2^21216472855 is an apocalyptic number.

21216472855 is a deficient number, since it is larger than the sum of its proper divisors (5762475785).

21216472855 is a wasteful number, since it uses less digits than its factorization.

21216472855 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 199538.

The product of its digits is 268800, while the sum is 43.

The spelling of 21216472855 in words is "twenty-one billion, two hundred sixteen million, four hundred seventy-two thousand, eight hundred fifty-five".