21036306 has 64 divisors (see below), whose sum is σ = 47278080. Its totient is φ = 6209280.

The previous prime is 21036299. The next prime is 21036311. The reversal of 21036306 is 60363012.

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 31 ways as a sum of consecutive naturals, for example, 186106 + ... + 186218.

It is an arithmetic number, because the mean of its divisors is an integer number (738720).

Almost surely, 2^21036306 is an apocalyptic number.

21036306 is an abundant number, since it is smaller than the sum of its proper divisors (26241774).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

21036306 is a wasteful number, since it uses less digits than its factorization.

21036306 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 231.

The product of its (nonzero) digits is 648, while the sum is 21.

The square root of 21036306 is about 4586.5352936612. The cubic root of 21036306 is about 276.0513189597.

Adding to 21036306 its reverse (60363012), we get a palindrome (81399318).

The spelling of 21036306 in words is "twenty-one million, thirty-six thousand, three hundred six".