21004932 has 48 divisors (see below), whose sum is σ = 54613440. Its totient is φ = 6238848.

The previous prime is 21004931. The next prime is 21004981. The reversal of 21004932 is 23940012.

It is a junction number, because it is equal to n+sod(n) for n = 21004899 and 21004908.

It is not an unprimeable number, because it can be changed into a prime (21004931) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 2203 + ... + 6845.

It is an arithmetic number, because the mean of its divisors is an integer number (1137780).

Almost surely, 2^21004932 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 21004932, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (27306720).

21004932 is an abundant number, since it is smaller than the sum of its proper divisors (33608508).

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

21004932 is a wasteful number, since it uses less digits than its factorization.

21004932 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4692 (or 4690 counting only the distinct ones).

The product of its (nonzero) digits is 432, while the sum is 21.

The square root of 21004932 is about 4583.1137886812. The cubic root of 21004932 is about 275.9140143825.

Adding to 21004932 its reverse (23940012), we get a palindrome (44944944).

The spelling of 21004932 in words is "twenty-one million, four thousand, nine hundred thirty-two".