21063984 has 20 divisors (see below), whose sum is σ = 54415416. Its totient is φ = 7021312.

The previous prime is 21063983. The next prime is 21063997. The reversal of 21063984 is 48936012.

It is not an unprimeable number, because it can be changed into a prime (21063983) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 219369 + ... + 219464.

Almost surely, 2^21063984 is an apocalyptic number.

21063984 is a gapful number since it is divisible by the number (24) formed by its first and last digit.

It is an amenable number.

21063984 is an abundant number, since it is smaller than the sum of its proper divisors (33351432).

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

21063984 is a wasteful number, since it uses less digits than its factorization.

21063984 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 438844 (or 438838 counting only the distinct ones).

The product of its (nonzero) digits is 10368, while the sum is 33.

The square root of 21063984 is about 4589.5516120859. The cubic root of 21063984 is about 276.1723351352.

Adding to 21063984 its reverse (48936012), we get a palindrome (69999996).

The spelling of 21063984 in words is "twenty-one million, sixty-three thousand, nine hundred eighty-four".