21105016 has 16 divisors (see below), whose sum is σ = 39936600. Its totient is φ = 10455264.

The previous prime is 21105013. The next prime is 21105023. The reversal of 21105016 is 61050112.

It is a happy number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21105013) 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, 11230 + ... + 12973.

Almost surely, 2^21105016 is an apocalyptic number.

It is an amenable number.

21105016 is a deficient number, since it is larger than the sum of its proper divisors (18831584).

21105016 is a wasteful number, since it uses less digits than its factorization.

21105016 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 24318 (or 24314 counting only the distinct ones).

The product of its (nonzero) digits is 60, while the sum is 16.

The square root of 21105016 is about 4594.0195907288. The cubic root of 21105016 is about 276.3515439234.

Adding to 21105016 its reverse (61050112), we get a palindrome (82155128).

The spelling of 21105016 in words is "twenty-one million, one hundred five thousand, sixteen".