21679168 has 84 divisors (see below), whose sum is σ = 51889152. Its totient is φ = 8951040.

The previous prime is 21679159. The next prime is 21679169. The reversal of 21679168 is 86197612.

It is a super-3 number, since 3×21679168³ (a number of 23 digits) contains 333 as substring.

It is a self number, because there is not a number n which added to its sum of digits gives 21679168.

It is not an unprimeable number, because it can be changed into a prime (21679169) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 97105 + ... + 97327.

It is an arithmetic number, because the mean of its divisors is an integer number (617728).

Almost surely, 2^21679168 is an apocalyptic number.

21679168 is a gapful number since it is divisible by the number (28) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 21679168, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (25944576).

21679168 is an abundant number, since it is smaller than the sum of its proper divisors (30209984).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

21679168 is a wasteful number, since it uses less digits than its factorization.

21679168 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 280 (or 263 counting only the distinct ones).

The product of its digits is 36288, while the sum is 40.

The square root of 21679168 is about 4656.0893462218. The cubic root of 21679168 is about 278.8351608259.

It can be divided in two parts, 2167 and 9168, that multiplied together give a triangular number (19867056 = T₆₃₀₃).

The spelling of 21679168 in words is "twenty-one million, six hundred seventy-nine thousand, one hundred sixty-eight".