21416216 has 16 divisors (see below), whose sum is σ = 40249440. Its totient is φ = 10683040.

The previous prime is 21416183. The next prime is 21416281. The reversal of 21416216 is 61261412.

It is a junction number, because it is equal to n+sod(n) for n = 21416191 and 21416200.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 785 + ... + 6591.

It is an arithmetic number, because the mean of its divisors is an integer number (2515590).

Almost surely, 2^21416216 is an apocalyptic number.

It is an amenable number.

21416216 is a deficient number, since it is larger than the sum of its proper divisors (18833224).

21416216 is a wasteful number, since it uses less digits than its factorization.

21416216 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 6274 (or 6270 counting only the distinct ones).

The product of its digits is 576, while the sum is 23.

The square root of 21416216 is about 4627.7657676248. The cubic root of 21416216 is about 277.7032182942.

Adding to 21416216 its reverse (61261412), we get a palindrome (82677628).

The spelling of 21416216 in words is "twenty-one million, four hundred sixteen thousand, two hundred sixteen".