21685367218834 has 64 divisors (see below), whose sum is σ = 37799737178112. Its totient is φ = 9221208480000.

The previous prime is 21685367218819. The next prime is 21685367218847. The reversal of 21685367218834 is 43881276358612.

It is a Smith number, since the sum of its digits (64) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

It is an unprimeable number.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 45479467 + ... + 45953809.

It is an arithmetic number, because the mean of its divisors is an integer number (590620893408).

Almost surely, 2^{21685367218834} is an apocalyptic number.

21685367218834 is a deficient number, since it is larger than the sum of its proper divisors (16114369959278).

21685367218834 is a wasteful number, since it uses less digits than its factorization.

21685367218834 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 475111.

The product of its digits is 92897280, while the sum is 64.

The spelling of 21685367218834 in words is "twenty-one trillion, six hundred eighty-five billion, three hundred sixty-seven million, two hundred eighteen thousand, eight hundred thirty-four".