21016672 has 12 divisors (see below), whose sum is σ = 41376636. Its totient is φ = 10508320.

The previous prime is 21016669. The next prime is 21016691. The reversal of 21016672 is 27661012.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (7) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 328354 + ... + 328417.

It is an arithmetic number, because the mean of its divisors is an integer number (3448053).

Almost surely, 2^21016672 is an apocalyptic number.

It is an amenable number.

21016672 is a deficient number, since it is larger than the sum of its proper divisors (20359964).

21016672 is an equidigital number, since it uses as much as digits as its factorization.

21016672 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 656781 (or 656773 counting only the distinct ones).

The product of its (nonzero) digits is 1008, while the sum is 25.

The square root of 21016672 is about 4584.3943983911. The cubic root of 21016672 is about 275.9654090935.

Adding to 21016672 its reverse (27661012), we get a palindrome (48677684).

The spelling of 21016672 in words is "twenty-one million, sixteen thousand, six hundred seventy-two".