21645112 has 16 divisors (see below), whose sum is σ = 40638600. Its totient is φ = 10808160.

The previous prime is 21645109. The next prime is 21645133. The reversal of 21645112 is 21154612.

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 3 ways as a sum of consecutive naturals, for example, 7287 + ... + 9817.

Almost surely, 2^21645112 is an apocalyptic number.

It is an amenable number.

21645112 is a deficient number, since it is larger than the sum of its proper divisors (18993488).

21645112 is a wasteful number, since it uses less digits than its factorization.

21645112 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3606 (or 3602 counting only the distinct ones).

The product of its digits is 480, while the sum is 22.

The square root of 21645112 is about 4652.4307625154. The cubic root of 21645112 is about 278.6890760832.

Adding to 21645112 its reverse (21154612), we get a palindrome (42799724).

The spelling of 21645112 in words is "twenty-one million, six hundred forty-five thousand, one hundred twelve".