21122686 has 16 divisors (see below), whose sum is σ = 34273008. Its totient is φ = 9705600.

The previous prime is 21122677. The next prime is 21122707. The reversal of 21122686 is 68622112.

It is a congruent number.

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 7 ways as a sum of consecutive naturals, for example, 4581 + ... + 7951.

It is an arithmetic number, because the mean of its divisors is an integer number (2142063).

Almost surely, 2^21122686 is an apocalyptic number.

21122686 is a gapful number since it is divisible by the number (26) formed by its first and last digit.

21122686 is a deficient number, since it is larger than the sum of its proper divisors (13150322).

21122686 is a wasteful number, since it uses less digits than its factorization.

21122686 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3627.

The product of its digits is 2304, while the sum is 28.

The square root of 21122686 is about 4595.9423408045. The cubic root of 21122686 is about 276.4286467573.

Adding to 21122686 its reverse (68622112), we get a palindrome (89744798).

The spelling of 21122686 in words is "twenty-one million, one hundred twenty-two thousand, six hundred eighty-six".