21033439 has 8 divisors (see below), whose sum is σ = 24867360. Its totient is φ = 17406816.

The previous prime is 21033433. The next prime is 21033443. The reversal of 21033439 is 93433012.

It is a happy number.

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

It is not a de Polignac number, because 21033439 - 2¹¹ = 21031391 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21033433) 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, 51604 + ... + 52009.

It is an arithmetic number, because the mean of its divisors is an integer number (3108420).

Almost surely, 2^21033439 is an apocalyptic number.

21033439 is a gapful number since it is divisible by the number (29) formed by its first and last digit.

21033439 is a deficient number, since it is larger than the sum of its proper divisors (3833921).

21033439 is a wasteful number, since it uses less digits than its factorization.

21033439 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 103649.

The product of its (nonzero) digits is 1944, while the sum is 25.

The square root of 21033439 is about 4586.2227377222. Note that the first 3 decimals coincide. The cubic root of 21033439 is about 276.0387775453.

The spelling of 21033439 in words is "twenty-one million, thirty-three thousand, four hundred thirty-nine".