21802808 has 16 divisors (see below), whose sum is σ = 40966560. Its totient is φ = 10878400.

The previous prime is 21802793. The next prime is 21802811. The reversal of 21802808 is 80820812.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1553 + ... + 6783.

It is an arithmetic number, because the mean of its divisors is an integer number (2560410).

Almost surely, 2^21802808 is an apocalyptic number.

It is an amenable number.

21802808 is a deficient number, since it is larger than the sum of its proper divisors (19163752).

21802808 is a wasteful number, since it uses less digits than its factorization.

21802808 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5758 (or 5754 counting only the distinct ones).

The product of its (nonzero) digits is 2048, while the sum is 29.

The square root of 21802808 is about 4669.3477060506. The cubic root of 21802808 is about 279.3642378163.

The spelling of 21802808 in words is "twenty-one million, eight hundred two thousand, eight hundred eight".