21711116665 has 32 divisors (see below), whose sum is σ = 30312463104. Its totient is φ = 14621368320.

The previous prime is 21711116657. The next prime is 21711116717. The reversal of 21711116665 is 56661111712.

It is not a de Polignac number, because 21711116665 - 2³ = 21711116657 is a prime.

It is an unprimeable number.

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 31 ways as a sum of consecutive naturals, for example, 420337 + ... + 469153.

It is an arithmetic number, because the mean of its divisors is an integer number (947264472).

Almost surely, 2^21711116665 is an apocalyptic number.

It is an amenable number.

21711116665 is a deficient number, since it is larger than the sum of its proper divisors (8601346439).

21711116665 is a wasteful number, since it uses less digits than its factorization.

21711116665 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 49057.

The product of its digits is 15120, while the sum is 37.

The spelling of 21711116665 in words is "twenty-one billion, seven hundred eleven million, one hundred sixteen thousand, six hundred sixty-five".