21385338 has 16 divisors (see below), whose sum is σ = 46060896. Its totient is φ = 6580080.

The previous prime is 21385327. The next prime is 21385339. The reversal of 21385338 is 83358312.

It is a Curzon number.

It is a junction number, because it is equal to n+sod(n) for n = 21385299 and 21385308.

It is not an unprimeable number, because it can be changed into a prime (21385339) 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 in 7 ways as a sum of consecutive naturals, for example, 137008 + ... + 137163.

It is an arithmetic number, because the mean of its divisors is an integer number (2878806).

Almost surely, 2^21385338 is an apocalyptic number.

21385338 is an abundant number, since it is smaller than the sum of its proper divisors (24675558).

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

21385338 is a wasteful number, since it uses less digits than its factorization.

21385338 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 274189.

The product of its digits is 17280, while the sum is 33.

The square root of 21385338 is about 4624.4283971103. The cubic root of 21385338 is about 277.5696895015.

The spelling of 21385338 in words is "twenty-one million, three hundred eighty-five thousand, three hundred thirty-eight".