21282912 has 288 divisors, whose sum is σ = 79252992. Its totient is φ = 5474304.

The previous prime is 21282901. The next prime is 21282923. The reversal of 21282912 is 21928212.

It is an interprime number because it is at equal distance from previous prime (21282901) and next prime (21282923).

It is a tau number, because it is divible by the number of its divisors (288).

It is a Harshad number since it is a multiple of its sum of digits (27).

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

Its product of digits (1152) is a multiple of the sum of its prime factors (72).

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (7) of ones.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 925333 + ... + 925355.

It is an arithmetic number, because the mean of its divisors is an integer number (275184).

Almost surely, 2^21282912 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 21282912, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (39626496).

21282912 is an abundant number, since it is smaller than the sum of its proper divisors (57970080).

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

21282912 is a wasteful number, since it uses less digits than its factorization.

21282912 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 72 (or 52 counting only the distinct ones).

The product of its digits is 1152, while the sum is 27.

The square root of 21282912 is about 4613.3406551002. The cubic root of 21282912 is about 277.1258361217.

The spelling of 21282912 in words is "twenty-one million, two hundred eighty-two thousand, nine hundred twelve".