21563334 has 48 divisors (see below), whose sum is σ = 52193232. Its totient is φ = 6632928.

The previous prime is 21563329. The next prime is 21563363. The reversal of 21563334 is 43336512.

It is a happy number.

21563334 is a `hidden beast` number, since 21 + 5 + 633 + 3 + 4 = 666.

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

It is a junction number, because it is equal to n+sod(n) for n = 21563298 and 21563307.

It is a congruent number.

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, 4612 + ... + 8024.

It is an arithmetic number, because the mean of its divisors is an integer number (1087359).

Almost surely, 2^21563334 is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 21563334, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (26096616).

21563334 is an abundant number, since it is smaller than the sum of its proper divisors (30629898).

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

21563334 is a wasteful number, since it uses less digits than its factorization.

21563334 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3443 (or 3431 counting only the distinct ones).

The product of its digits is 6480, while the sum is 27.

The square root of 21563334 is about 4643.6337064846. The cubic root of 21563334 is about 278.3376588266.

Adding to 21563334 its reverse (43336512), we get a palindrome (64899846).

The spelling of 21563334 in words is "twenty-one million, five hundred sixty-three thousand, three hundred thirty-four".