21032216 has 24 divisors (see below), whose sum is σ = 39992220. Its totient is φ = 10369296.

The previous prime is 21032201. The next prime is 21032237. The reversal of 21032216 is 61223012.

It is a junction number, because it is equal to n+sod(n) for n = 21032194 and 21032203.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 128951 + ... + 129113.

Almost surely, 2^21032216 is an apocalyptic number.

It is an amenable number.

21032216 is a deficient number, since it is larger than the sum of its proper divisors (18960004).

21032216 is a wasteful number, since it uses less digits than its factorization.

21032216 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 423 (or 292 counting only the distinct ones).

The product of its (nonzero) digits is 144, while the sum is 17.

The square root of 21032216 is about 4586.0894016580. The cubic root of 21032216 is about 276.0334273033.

Adding to 21032216 its reverse (61223012), we get a palindrome (82255228).

The spelling of 21032216 in words is "twenty-one million, thirty-two thousand, two hundred sixteen".