21329168 has 40 divisors (see below), whose sum is σ = 48514752. Its totient is φ = 8892288.

The previous prime is 21329167. The next prime is 21329177. The reversal of 21329168 is 86192312.

It is not an unprimeable number, because it can be changed into a prime (21329167) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 1571 + ... + 6717.

Almost surely, 2^21329168 is an apocalyptic number.

21329168 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 21329168, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (24257376).

21329168 is an abundant number, since it is smaller than the sum of its proper divisors (27185584).

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

21329168 is a wasteful number, since it uses less digits than its factorization.

21329168 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5199 (or 5193 counting only the distinct ones).

The product of its digits is 5184, while the sum is 32.

The square root of 21329168 is about 4618.3512209445. The cubic root of 21329168 is about 277.3264580602.

The spelling of 21329168 in words is "twenty-one million, three hundred twenty-nine thousand, one hundred sixty-eight".