21317086 has 16 divisors (see below), whose sum is σ = 36900864. Its totient is φ = 9046584.

The previous prime is 21317083. The next prime is 21317129. The reversal of 21317086 is 68071312.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21317081) 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 7 ways as a sum of consecutive naturals, for example, 5950 + ... + 8833.

It is an arithmetic number, because the mean of its divisors is an integer number (2306304).

Almost surely, 2^21317086 is an apocalyptic number.

21317086 is a deficient number, since it is larger than the sum of its proper divisors (15583778).

21317086 is a wasteful number, since it uses less digits than its factorization.

21317086 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 14895.

The product of its (nonzero) digits is 2016, while the sum is 28.

The square root of 21317086 is about 4617.0429930855. The cubic root of 21317086 is about 277.2740839102.

Adding to 21317086 its reverse (68071312), we get a palindrome (89388398).

The spelling of 21317086 in words is "twenty-one million, three hundred seventeen thousand, eighty-six".