21500032 has 64 divisors (see below), whose sum is σ = 45777600. Its totient is φ = 10036224.

The previous prime is 21500029. The next prime is 21500069. The reversal of 21500032 is 23000512.

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

It is a zygodrome in base 3.

It is a junction number, because it is equal to n+sod(n) for n = 21499985 and 21500021.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (5) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 197194 + ... + 197302.

It is an arithmetic number, because the mean of its divisors is an integer number (715275).

Almost surely, 2^21500032 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 21500032, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (22888800).

21500032 is an abundant number, since it is smaller than the sum of its proper divisors (24277568).

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

21500032 is a wasteful number, since it uses less digits than its factorization.

21500032 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 213 (or 201 counting only the distinct ones).

The product of its (nonzero) digits is 60, while the sum is 13.

The square root of 21500032 is about 4636.8126983953. The cubic root of 21500032 is about 278.0650262807.

Adding to 21500032 its reverse (23000512), we get a palindrome (44500544).

The spelling of 21500032 in words is "twenty-one million, five hundred thousand, thirty-two".