21717216867 has 8 divisors (see below), whose sum is σ = 28956973824. Its totient is φ = 14477802248.

The previous prime is 21717216793. The next prime is 21717216887. The reversal of 21717216867 is 76861271712.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 21717216867 - 2⁷ = 21717216739 is a prime.

It is not an unprimeable number, because it can be changed into a prime (21717216887) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 181618 + ... + 276440.

It is an arithmetic number, because the mean of its divisors is an integer number (3619621728).

Almost surely, 2^21717216867 is an apocalyptic number.

21717216867 is a deficient number, since it is larger than the sum of its proper divisors (7239756957).

21717216867 is an equidigital number, since it uses as much as digits as its factorization.

21717216867 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 171169.

The product of its digits is 395136, while the sum is 48.

The spelling of 21717216867 in words is "twenty-one billion, seven hundred seventeen million, two hundred sixteen thousand, eight hundred sixty-seven".