21928443 has 8 divisors (see below), whose sum is σ = 29566800. Its totient is φ = 14454528.

The previous prime is 21928433. The next prime is 21928447. The reversal of 21928443 is 34482912.

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 21928443 - 2⁹ = 21927931 is a prime.

It is a super-3 number, since 3×21928443³ (a number of 23 digits) contains 333 as substring. Note that it is a super-d number also for d = 2.

It is not an unprimeable number, because it can be changed into a prime (21928447) 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, 40798 + ... + 41331.

It is an arithmetic number, because the mean of its divisors is an integer number (3695850).

Almost surely, 2^21928443 is an apocalyptic number.

21928443 is a deficient number, since it is larger than the sum of its proper divisors (7638357).

21928443 is an equidigital number, since it uses as much as digits as its factorization.

21928443 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 82221.

The product of its digits is 13824, while the sum is 33.

The square root of 21928443 is about 4682.7815451930. The cubic root of 21928443 is about 279.8998068390.

The spelling of 21928443 in words is "twenty-one million, nine hundred twenty-eight thousand, four hundred forty-three".