21516838 has 16 divisors (see below), whose sum is σ = 37253664. Its totient is φ = 9129600.

The previous prime is 21516829. The next prime is 21516853. The reversal of 21516838 is 83861512.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 6195 + ... + 9022.

It is an arithmetic number, because the mean of its divisors is an integer number (2328354).

Almost surely, 2^21516838 is an apocalyptic number.

21516838 is a deficient number, since it is larger than the sum of its proper divisors (15736826).

21516838 is a wasteful number, since it uses less digits than its factorization.

21516838 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 15327.

The product of its digits is 11520, while the sum is 34.

The square root of 21516838 is about 4638.6245806273. The cubic root of 21516838 is about 278.1374594090.

The spelling of 21516838 in words is "twenty-one million, five hundred sixteen thousand, eight hundred thirty-eight".