21214416 has 80 divisors (see below), whose sum is σ = 57853440. Its totient is φ = 6689280.

The previous prime is 21214381. The next prime is 21214429. The reversal of 21214416 is 61441212.

It is a happy number.

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 = 21214392 and 21214401.

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 15 ways as a sum of consecutive naturals, for example, 78730 + ... + 78998.

It is an arithmetic number, because the mean of its divisors is an integer number (723168).

Almost surely, 2^21214416 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 21214416, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (28926720).

21214416 is an abundant number, since it is smaller than the sum of its proper divisors (36639024).

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

21214416 is a wasteful number, since it uses less digits than its factorization.

21214416 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 364 (or 358 counting only the distinct ones).

The product of its digits is 384, while the sum is 21.

The square root of 21214416 is about 4605.9109848107. The cubic root of 21214416 is about 276.8282200282.

Adding to 21214416 its reverse (61441212), we get a palindrome (82655628).

The spelling of 21214416 in words is "twenty-one million, two hundred fourteen thousand, four hundred sixteen".