21104216 has 32 divisors (see below), whose sum is σ = 45476640. Its totient is φ = 8994048.

The previous prime is 21104203. The next prime is 21104221. The reversal of 21104216 is 61240112.

It is a junction number, because it is equal to n+sod(n) for n = 21104194 and 21104203.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 10076 + ... + 11988.

It is an arithmetic number, because the mean of its divisors is an integer number (1421145).

Almost surely, 2^21104216 is an apocalyptic number.

It is an amenable number.

21104216 is an abundant number, since it is smaller than the sum of its proper divisors (24372424).

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

21104216 is a wasteful number, since it uses less digits than its factorization.

21104216 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2123 (or 2119 counting only the distinct ones).

The product of its (nonzero) digits is 96, while the sum is 17.

The square root of 21104216 is about 4593.9325201836. The cubic root of 21104216 is about 276.3480521148.

Adding to 21104216 its reverse (61240112), we get a palindrome (82344328).

The spelling of 21104216 in words is "twenty-one million, one hundred four thousand, two hundred sixteen".