21675423178 has 16 divisors (see below), whose sum is σ = 33310238976. Its totient is φ = 10572075360.

The previous prime is 21675423173. The next prime is 21675423179. The reversal of 21675423178 is 87132457612.

It is not an unprimeable number, because it can be changed into a prime (21675423173) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 1269325 + ... + 1286287.

It is an arithmetic number, because the mean of its divisors is an integer number (2081889936).

Almost surely, 2^21675423178 is an apocalyptic number.

21675423178 is a deficient number, since it is larger than the sum of its proper divisors (11634815798).

21675423178 is a wasteful number, since it uses less digits than its factorization.

21675423178 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 32589.

The product of its digits is 564480, while the sum is 46.

It can be divided in two parts, 216754 and 23178, that added together give a palindrome (239932).

The spelling of 21675423178 in words is "twenty-one billion, six hundred seventy-five million, four hundred twenty-three thousand, one hundred seventy-eight".