21086206 has 16 divisors (see below), whose sum is σ = 32207040. Its totient is φ = 10352160.

The previous prime is 21086203. The next prime is 21086227. The reversal of 21086206 is 60268012.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21086201) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 49876 + ... + 50296.

It is an arithmetic number, because the mean of its divisors is an integer number (2012940).

Almost surely, 2^21086206 is an apocalyptic number.

21086206 is a deficient number, since it is larger than the sum of its proper divisors (11120834).

21086206 is a wasteful number, since it uses less digits than its factorization.

21086206 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 819.

The product of its (nonzero) digits is 1152, while the sum is 25.

The square root of 21086206 is about 4591.9719075796. The cubic root of 21086206 is about 276.2694194084.

The spelling of 21086206 in words is "twenty-one million, eighty-six thousand, two hundred six".