21666868367 has 16 divisors (see below), whose sum is σ = 23049292800. Its totient is φ = 20309758560.

The previous prime is 21666868313. The next prime is 21666868393. The reversal of 21666868367 is 76386866612.

It is a cyclic number.

It is not a de Polignac number, because 21666868367 - 2²² = 21662674063 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21666861367) 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 15 ways as a sum of consecutive naturals, for example, 697742 + ... + 728132.

It is an arithmetic number, because the mean of its divisors is an integer number (1440580800).

Almost surely, 2^21666868367 is an apocalyptic number.

21666868367 is a deficient number, since it is larger than the sum of its proper divisors (1382424433).

21666868367 is a wasteful number, since it uses less digits than its factorization.

21666868367 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 30806.

The product of its digits is 20901888, while the sum is 59.

The spelling of 21666868367 in words is "twenty-one billion, six hundred sixty-six million, eight hundred sixty-eight thousand, three hundred sixty-seven".