21767115217 has 32 divisors (see below), whose sum is σ = 24229969920. Its totient is φ = 19471181760.

The previous prime is 21767115157. The next prime is 21767115221. The reversal of 21767115217 is 71251176712.

It is not a de Polignac number, because 21767115217 - 2¹¹ = 21767113169 is a prime.

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 21767115217.

It is not an unprimeable number, because it can be changed into a prime (21767115277) 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 31 ways as a sum of consecutive naturals, for example, 10601563 + ... + 10603615.

It is an arithmetic number, because the mean of its divisors is an integer number (757186560).

Almost surely, 2^21767115217 is an apocalyptic number.

It is an amenable number.

21767115217 is a deficient number, since it is larger than the sum of its proper divisors (2462854703).

21767115217 is a wasteful number, since it uses less digits than its factorization.

21767115217 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2533.

The product of its digits is 41160, while the sum is 40.

The spelling of 21767115217 in words is "twenty-one billion, seven hundred sixty-seven million, one hundred fifteen thousand, two hundred seventeen".