21284832 has 24 divisors (see below), whose sum is σ = 55872936. Its totient is φ = 7094912.

The previous prime is 21284801. The next prime is 21284839. The reversal of 21284832 is 23848212.

It is a tau number, because it is divible by the number of its divisors (24).

It is a nude number because it is divisible by every one of its digits.

It is a self number, because there is not a number n which added to its sum of digits gives 21284832.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21284839) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 110763 + ... + 110954.

It is an arithmetic number, because the mean of its divisors is an integer number (2328039).

Almost surely, 2^21284832 is an apocalyptic number.

It is an amenable number.

21284832 is an abundant number, since it is smaller than the sum of its proper divisors (34588104).

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

21284832 is a wasteful number, since it uses less digits than its factorization.

21284832 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 221730 (or 221722 counting only the distinct ones).

The product of its digits is 6144, while the sum is 30.

The square root of 21284832 is about 4613.5487425625. The cubic root of 21284832 is about 277.1341693424.

The spelling of 21284832 in words is "twenty-one million, two hundred eighty-four thousand, eight hundred thirty-two".