21041039 has 4 divisors (see below), whose sum is σ = 21102024. Its totient is φ = 20980056.

The previous prime is 21041029. The next prime is 21041047. The reversal of 21041039 is 93014012.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 21041039 - 2²⁴ = 4263823 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 21041039.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21041029) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 29972 + ... + 30665.

It is an arithmetic number, because the mean of its divisors is an integer number (5275506).

Almost surely, 2^21041039 is an apocalyptic number.

21041039 is a deficient number, since it is larger than the sum of its proper divisors (60985).

21041039 is an equidigital number, since it uses as much as digits as its factorization.

21041039 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 60984.

The product of its (nonzero) digits is 216, while the sum is 20.

The square root of 21041039 is about 4587.0512314558. The cubic root of 21041039 is about 276.0720205175.

The spelling of 21041039 in words is "twenty-one million, forty-one thousand, thirty-nine".