21146828 has 12 divisors (see below), whose sum is σ = 37222080. Its totient is φ = 10511952.

The previous prime is 21146813. The next prime is 21146831. The reversal of 21146828 is 82864112.

It is a happy number.

It is a junction number, because it is equal to n+sod(n) for n = 21146794 and 21146803.

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 3 ways as a sum of consecutive naturals, for example, 14588 + ... + 15971.

It is an arithmetic number, because the mean of its divisors is an integer number (3101840).

Almost surely, 2^21146828 is an apocalyptic number.

It is an amenable number.

21146828 is a deficient number, since it is larger than the sum of its proper divisors (16075252).

21146828 is a wasteful number, since it uses less digits than its factorization.

21146828 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 30736 (or 30734 counting only the distinct ones).

The product of its digits is 6144, while the sum is 32.

The square root of 21146828 is about 4598.5680379875. The cubic root of 21146828 is about 276.5339206085.

The spelling of 21146828 in words is "twenty-one million, one hundred forty-six thousand, eight hundred twenty-eight".