21899804 has 6 divisors (see below), whose sum is σ = 38324664. Its totient is φ = 10949900.

The previous prime is 21899803. The next prime is 21899831. The reversal of 21899804 is 40899812.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21899803) by changing a digit.

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 as a sum of consecutive naturals, namely, 2737472 + ... + 2737479.

It is an arithmetic number, because the mean of its divisors is an integer number (6387444).

Almost surely, 2^21899804 is an apocalyptic number.

It is an amenable number.

21899804 is a deficient number, since it is larger than the sum of its proper divisors (16424860).

21899804 is a wasteful number, since it uses less digits than its factorization.

21899804 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5474955 (or 5474953 counting only the distinct ones).

The product of its (nonzero) digits is 41472, while the sum is 41.

The square root of 21899804 is about 4679.7226413539. The cubic root of 21899804 is about 279.7779021083. Note that the first 3 decimals are identical.

The spelling of 21899804 in words is "twenty-one million, eight hundred ninety-nine thousand, eight hundred four".