21484736 has 168 divisors, whose sum is σ = 58375296. Its totient is φ = 7741440.

The previous prime is 21484721. The next prime is 21484747. The reversal of 21484736 is 63748412.

It is a plaindrome in base 11.

It is a junction number, because it is equal to n+sod(n) for n = 21484696 and 21484705.

It is an unprimeable number.

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 23 ways as a sum of consecutive naturals, for example, 693041 + ... + 693071.

It is an arithmetic number, because the mean of its divisors is an integer number (347472).

Almost surely, 2^21484736 is an apocalyptic number.

21484736 is a gapful number since it is divisible by the number (26) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 21484736, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (29187648).

21484736 is an abundant number, since it is smaller than the sum of its proper divisors (36890560).

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

21484736 is a wasteful number, since it uses less digits than its factorization.

21484736 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 87 (or 70 counting only the distinct ones).

The product of its digits is 32256, while the sum is 35.

The square root of 21484736 is about 4635.1629960553. The cubic root of 21484736 is about 277.9990683681. Note that the first 3 decimals are identical.

The spelling of 21484736 in words is "twenty-one million, four hundred eighty-four thousand, seven hundred thirty-six".