21628036 has 12 divisors (see below), whose sum is σ = 37882012. Its totient is φ = 10804608.

The previous prime is 21628031. The next prime is 21628121. The reversal of 21628036 is 63082612.

It can be written as a sum of positive squares in 2 ways, for example, as 19360000 + 2268036 = 4400^2 + 1506^2 .

It is a junction number, because it is equal to n+sod(n) for n = 21627995 and 21628013.

It is not an unprimeable number, because it can be changed into a prime (21628031) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (7) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 6616 + ... + 9328.

Almost surely, 2^21628036 is an apocalyptic number.

It is an amenable number.

21628036 is a deficient number, since it is larger than the sum of its proper divisors (16253976).

21628036 is a wasteful number, since it uses less digits than its factorization.

21628036 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4710 (or 4708 counting only the distinct ones).

The product of its (nonzero) digits is 3456, while the sum is 28.

The square root of 21628036 is about 4650.5952307205. The cubic root of 21628036 is about 278.6157701308.

The spelling of 21628036 in words is "twenty-one million, six hundred twenty-eight thousand, thirty-six".