21046828 has 24 divisors (see below), whose sum is σ = 40388544. Its totient is φ = 9517200.

The previous prime is 21046819. The next prime is 21046841. The reversal of 21046828 is 82864012.

It is a self number, because there is not a number n which added to its sum of digits gives 21046828.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 8151 + ... + 10417.

It is an arithmetic number, because the mean of its divisors is an integer number (1682856).

Almost surely, 2^21046828 is an apocalyptic number.

It is an amenable number.

21046828 is a deficient number, since it is larger than the sum of its proper divisors (19341716).

21046828 is a wasteful number, since it uses less digits than its factorization.

21046828 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2493 (or 2491 counting only the distinct ones).

The product of its (nonzero) digits is 6144, while the sum is 31.

The square root of 21046828 is about 4587.6822034661. The cubic root of 21046828 is about 276.0973366688.

The spelling of 21046828 in words is "twenty-one million, forty-six thousand, eight hundred twenty-eight".