21038 has 8 divisors (see below), whose sum is σ = 32232. Its totient is φ = 10296.

The previous prime is 21031. The next prime is 21059. The reversal of 21038 is 83012.

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

It is an alternating number because its digits alternate between even and odd.

It is a nialpdrome in base 13.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21031) by changing a digit.

21038 is an untouchable number, because it is not equal to the sum of proper divisors of any number.

It is a pernicious number, because its binary representation contains a prime number (7) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 56 + ... + 212.

It is an arithmetic number, because the mean of its divisors is an integer number (4029).

2²¹⁰³⁸ is an apocalyptic number.

21038 is a deficient number, since it is larger than the sum of its proper divisors (11194).

21038 is a wasteful number, since it uses less digits than its factorization.

21038 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 226.

The product of its (nonzero) digits is 48, while the sum is 14.

The square root of 21038 is about 145.0448206590. The cubic root of 21038 is about 27.6058728663.

The spelling of 21038 in words is "twenty-one thousand, thirty-eight".