21320832 has 64 divisors (see below), whose sum is σ = 61004160. Its totient is φ = 6558720.

The previous prime is 21320821. The next prime is 21320833. The reversal of 21320832 is 23802312.

It is a tau number, because it is divible by the number of its divisors (64).

It is a junction number, because it is equal to n+sod(n) for n = 21320799 and 21320808.

It is not an unprimeable number, because it can be changed into a prime (21320833) 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, 2857 + ... + 7127.

It is an arithmetic number, because the mean of its divisors is an integer number (953190).

Almost surely, 2^21320832 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 21320832, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (30502080).

21320832 is an abundant number, since it is smaller than the sum of its proper divisors (39683328).

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

21320832 is a wasteful number, since it uses less digits than its factorization.

21320832 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4301 (or 4289 counting only the distinct ones).

The product of its (nonzero) digits is 576, while the sum is 21.

The square root of 21320832 is about 4617.4486461681. The cubic root of 21320832 is about 277.2903245271.

The spelling of 21320832 in words is "twenty-one million, three hundred twenty thousand, eight hundred thirty-two".