21681550085 has 64 divisors (see below), whose sum is σ = 30549657600. Its totient is φ = 14634079488.

The previous prime is 21681550019. The next prime is 21681550141. The reversal of 21681550085 is 58005518612.

It is a cyclic number.

It is not a de Polignac number, because 21681550085 - 2⁸ = 21681549829 is a prime.

It is a super-2 number, since 2×21681550085² (a number of 21 digits) contains 22 as substring.

It is a congruent number.

It is an unprimeable number.

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 63 ways as a sum of consecutive naturals, for example, 4405256 + ... + 4410174.

It is an arithmetic number, because the mean of its divisors is an integer number (477338400).

Almost surely, 2^21681550085 is an apocalyptic number.

It is an amenable number.

21681550085 is a deficient number, since it is larger than the sum of its proper divisors (8868107515).

21681550085 is a wasteful number, since it uses less digits than its factorization.

21681550085 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5082.

The product of its (nonzero) digits is 96000, while the sum is 41.

The spelling of 21681550085 in words is "twenty-one billion, six hundred eighty-one million, five hundred fifty thousand, eighty-five".