21963216 has 40 divisors (see below), whose sum is σ = 61897824. Its totient is φ = 6655360.

The previous prime is 21963209. The next prime is 21963247. The reversal of 21963216 is 61236912.

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 7 ways as a sum of consecutive naturals, for example, 20271 + ... + 21326.

Almost surely, 2^21963216 is an apocalyptic number.

It is an amenable number.

21963216 is an abundant number, since it is smaller than the sum of its proper divisors (39934608).

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

21963216 is a wasteful number, since it uses less digits than its factorization.

21963216 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 41619 (or 41613 counting only the distinct ones).

The product of its digits is 3888, while the sum is 30.

The square root of 21963216 is about 4686.4929318201. The cubic root of 21963216 is about 280.0476789555.

The spelling of 21963216 in words is "twenty-one million, nine hundred sixty-three thousand, two hundred sixteen".