21168213967 has 16 divisors (see below), whose sum is σ = 22694715072. Its totient is φ = 19692668160.

The previous prime is 21168213947. The next prime is 21168213971. The reversal of 21168213967 is 76931286112.

It is a cyclic number.

It is not a de Polignac number, because 21168213967 - 2¹¹ = 21168211919 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 (21168213947) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 3790117 + ... + 3795697.

It is an arithmetic number, because the mean of its divisors is an integer number (1418419692).

Almost surely, 2^21168213967 is an apocalyptic number.

21168213967 is a deficient number, since it is larger than the sum of its proper divisors (1526501105).

21168213967 is a wasteful number, since it uses less digits than its factorization.

21168213967 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 10098.

The product of its digits is 217728, while the sum is 46.

The spelling of 21168213967 in words is "twenty-one billion, one hundred sixty-eight million, two hundred thirteen thousand, nine hundred sixty-seven".