21016544 has 24 divisors (see below), whose sum is σ = 41543208. Its totient is φ = 10465920.

The previous prime is 21016519. The next prime is 21016547. The reversal of 21016544 is 44561012.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21016547) by changing a digit.

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, 7679 + ... + 10049.

It is an arithmetic number, because the mean of its divisors is an integer number (1730967).

Almost surely, 2^21016544 is an apocalyptic number.

It is an amenable number.

21016544 is a deficient number, since it is larger than the sum of its proper divisors (20526664).

21016544 is a wasteful number, since it uses less digits than its factorization.

21016544 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2658 (or 2650 counting only the distinct ones).

The product of its (nonzero) digits is 960, while the sum is 23.

The square root of 21016544 is about 4584.3804379654. The cubic root of 21016544 is about 275.9648488455.

Adding to 21016544 its reverse (44561012), we get a palindrome (65577556).

The spelling of 21016544 in words is "twenty-one million, sixteen thousand, five hundred forty-four".