21716115 has 16 divisors (see below), whose sum is σ = 35486208. Its totient is φ = 11335136.

The previous prime is 21716087. The next prime is 21716137. The reversal of 21716115 is 51161712.

It is a cyclic number.

It is not a de Polignac number, because 21716115 - 2¹¹ = 21714067 is a prime.

It is an unprimeable number.

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, 14697 + ... + 16106.

It is an arithmetic number, because the mean of its divisors is an integer number (2217888).

Almost surely, 2^21716115 is an apocalyptic number.

21716115 is a deficient number, since it is larger than the sum of its proper divisors (13770093).

21716115 is a wasteful number, since it uses less digits than its factorization.

21716115 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 30858.

The product of its digits is 420, while the sum is 24.

The square root of 21716115 is about 4660.0552571831. The cubic root of 21716115 is about 278.9934737236.

Adding to 21716115 its reverse (51161712), we get a palindrome (72877827).

The spelling of 21716115 in words is "twenty-one million, seven hundred sixteen thousand, one hundred fifteen".