21838443 has 12 divisors (see below), whose sum is σ = 32006184. Its totient is φ = 13235200.

The previous prime is 21838441. The next prime is 21838451. The reversal of 21838443 is 34483812.

It is not a de Polignac number, because 21838443 - 2¹ = 21838441 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (33).

It is not an unprimeable number, because it can be changed into a prime (21838441) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 29718 + ... + 30443.

It is an arithmetic number, because the mean of its divisors is an integer number (2667182).

Almost surely, 2^21838443 is an apocalyptic number.

21838443 is a deficient number, since it is larger than the sum of its proper divisors (10167741).

21838443 is a wasteful number, since it uses less digits than its factorization.

21838443 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 60186 (or 60175 counting only the distinct ones).

The product of its digits is 18432, while the sum is 33.

The square root of 21838443 is about 4673.1619916284. The cubic root of 21838443 is about 279.5163547041.

The spelling of 21838443 in words is "twenty-one million, eight hundred thirty-eight thousand, four hundred forty-three".