21254216 has 48 divisors (see below), whose sum is σ = 43931700. Its totient is φ = 9626624.

The previous prime is 21254213. The next prime is 21254221. The reversal of 21254216 is 61245212.

It is a happy number.

It can be written as a sum of positive squares in 6 ways, for example, as 11356900 + 9897316 = 3370^2 + 3146^2 .

It is a junction number, because it is equal to n+sod(n) for n = 21254191 and 21254200.

It is not an unprimeable number, because it can be changed into a prime (21254213) by changing a digit.

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 11 ways as a sum of consecutive naturals, for example, 66890 + ... + 67206.

Almost surely, 2^21254216 is an apocalyptic number.

It is an amenable number.

21254216 is an abundant number, since it is smaller than the sum of its proper divisors (22677484).

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

21254216 is a wasteful number, since it uses less digits than its factorization.

21254216 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 386 (or 365 counting only the distinct ones).

The product of its digits is 960, while the sum is 23.

The square root of 21254216 is about 4610.2294953722. The cubic root of 21254216 is about 277.0012294297.

Adding to 21254216 its reverse (61245212), we get a palindrome (82499428).

The spelling of 21254216 in words is "twenty-one million, two hundred fifty-four thousand, two hundred sixteen".