21046216 has 16 divisors (see below), whose sum is σ = 39524940. Its totient is φ = 10506240.

The previous prime is 21046171. The next prime is 21046217. The reversal of 21046216 is 61264012.

It can be written as a sum of positive squares in 2 ways, for example, as 12320100 + 8726116 = 3510^2 + 2954^2 .

It is not an unprimeable number, because it can be changed into a prime (21046217) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 4360 + ... + 7816.

Almost surely, 2^21046216 is an apocalyptic number.

It is an amenable number.

21046216 is a deficient number, since it is larger than the sum of its proper divisors (18478724).

21046216 is a wasteful number, since it uses less digits than its factorization.

21046216 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4224 (or 4220 counting only the distinct ones).

The product of its (nonzero) digits is 576, while the sum is 22.

The square root of 21046216 is about 4587.6155026331. The cubic root of 21046216 is about 276.0946605220.

The spelling of 21046216 in words is "twenty-one million, forty-six thousand, two hundred sixteen".