21804048 has 120 divisors (see below), whose sum is σ = 70773248. Its totient is φ = 6137856.

The previous prime is 21804043. The next prime is 21804073. The reversal of 21804048 is 84040812.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21804043) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 97665 + ... + 97887.

Almost surely, 2^21804048 is an apocalyptic number.

21804048 is a gapful number since it is divisible by the number (28) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 21804048, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (35386624).

21804048 is an abundant number, since it is smaller than the sum of its proper divisors (48969200).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

21804048 is a wasteful number, since it uses less digits than its factorization.

21804048 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 341 (or 332 counting only the distinct ones).

The product of its (nonzero) digits is 2048, while the sum is 27.

The square root of 21804048 is about 4669.4804850219. The cubic root of 21804048 is about 279.3695338480.

It can be divided in two parts, 2 and 1804048, that added together give a triangular number (1804050 = T₁₈₉₉).

The spelling of 21804048 in words is "twenty-one million, eight hundred four thousand, forty-eight".