21412224 has 48 divisors (see below), whose sum is σ = 61619220. Its totient is φ = 7137024.

The previous prime is 21412219. The next prime is 21412267. The reversal of 21412224 is 42221412.

It is a tau number, because it is divible by the number of its divisors (48).

It is a Harshad number since it is a multiple of its sum of digits (18).

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

It is a junction number, because it is equal to n+sod(n) for n = 21412197 and 21412206.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 8142 + ... + 10445.

Almost surely, 2^21412224 is an apocalyptic number.

21412224 is a gapful number since it is divisible by the number (24) formed by its first and last digit.

It is an amenable number.

21412224 is an abundant number, since it is smaller than the sum of its proper divisors (40206996).

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

21412224 is a wasteful number, since it uses less digits than its factorization.

21412224 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 18607 (or 18592 counting only the distinct ones).

The product of its digits is 256, while the sum is 18.

The square root of 21412224 is about 4627.3344378811. The cubic root of 21412224 is about 277.6859625204.

Adding to 21412224 its reverse (42221412), we get a palindrome (63633636).

The spelling of 21412224 in words is "twenty-one million, four hundred twelve thousand, two hundred twenty-four".