21667845206 has 16 divisors (see below), whose sum is σ = 38148794016. Its totient is φ = 9035240256.

The previous prime is 21667845203. The next prime is 21667845209. The reversal of 21667845206 is 60254876612.

It is an interprime number because it is at equal distance from previous prime (21667845203) and next prime (21667845209).

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21667845203) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 20914391 + ... + 20915426.

It is an arithmetic number, because the mean of its divisors is an integer number (2384299626).

Almost surely, 2^21667845206 is an apocalyptic number.

21667845206 is a deficient number, since it is larger than the sum of its proper divisors (16480948810).

21667845206 is a wasteful number, since it uses less digits than its factorization.

21667845206 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 41829863.

The product of its (nonzero) digits is 967680, while the sum is 47.

The spelling of 21667845206 in words is "twenty-one billion, six hundred sixty-seven million, eight hundred forty-five thousand, two hundred six".