21083686 has 16 divisors (see below), whose sum is σ = 35540064. Its totient is φ = 9307584.

The previous prime is 21083669. The next prime is 21083719. The reversal of 21083686 is 68638012.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 17031 + ... + 18226.

It is an arithmetic number, because the mean of its divisors is an integer number (2221254).

Almost surely, 2^21083686 is an apocalyptic number.

21083686 is a gapful number since it is divisible by the number (26) formed by its first and last digit.

21083686 is a deficient number, since it is larger than the sum of its proper divisors (14456378).

21083686 is a wasteful number, since it uses less digits than its factorization.

21083686 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 35295.

The product of its (nonzero) digits is 13824, while the sum is 34.

The square root of 21083686 is about 4591.6975074584. The cubic root of 21083686 is about 276.2584133717.

The spelling of 21083686 in words is "twenty-one million, eighty-three thousand, six hundred eighty-six".