21016508 has 48 divisors (see below), whose sum is σ = 40656000. Its totient is φ = 9471168.

The previous prime is 21016507. The next prime is 21016517. The reversal of 21016508 is 80561012.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21016507) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 192758 + ... + 192866.

It is an arithmetic number, because the mean of its divisors is an integer number (847000).

Almost surely, 2^21016508 is an apocalyptic number.

It is an amenable number.

21016508 is a deficient number, since it is larger than the sum of its proper divisors (19639492).

21016508 is a wasteful number, since it uses less digits than its factorization.

21016508 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 234 (or 232 counting only the distinct ones).

The product of its (nonzero) digits is 480, while the sum is 23.

The square root of 21016508 is about 4584.3765115880. The cubic root of 21016508 is about 275.9646912753.

The spelling of 21016508 in words is "twenty-one million, sixteen thousand, five hundred eight".