21841424 has 40 divisors (see below), whose sum is σ = 46476192. Its totient is φ = 9861120.

The previous prime is 21841409. The next prime is 21841427. The reversal of 21841424 is 42414812.

It is a nude number because it is divisible by every one of its digits.

It is a junction number, because it is equal to n+sod(n) for n = 21841393 and 21841402.

It is not an unprimeable number, because it can be changed into a prime (21841427) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 33647 + ... + 34289.

Almost surely, 2^21841424 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 21841424, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (23238096).

21841424 is an abundant number, since it is smaller than the sum of its proper divisors (24634768).

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

21841424 is a wasteful number, since it uses less digits than its factorization.

21841424 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 855 (or 849 counting only the distinct ones).

The product of its digits is 2048, while the sum is 26.

The square root of 21841424 is about 4673.4809296712. The cubic root of 21841424 is about 279.5290723437.

The spelling of 21841424 in words is "twenty-one million, eight hundred forty-one thousand, four hundred twenty-four".