21017041 has 4 divisors (see below), whose sum is σ = 21026212. Its totient is φ = 21007872.

The previous prime is 21017027. The next prime is 21017063. The reversal of 21017041 is 14071012.

It is a semiprime because it is the product of two primes, and also a brilliant number, because the two primes have the same length.

It can be written as a sum of positive squares in 2 ways, for example, as 731025 + 20286016 = 855^2 + 4504^2 .

It is a cyclic number.

It is not a de Polignac number, because 21017041 - 2¹³ = 21008849 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21017071) 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, 2185 + ... + 6841.

It is an arithmetic number, because the mean of its divisors is an integer number (5256553).

Almost surely, 2^21017041 is an apocalyptic number.

It is an amenable number.

21017041 is a deficient number, since it is larger than the sum of its proper divisors (9171).

21017041 is an equidigital number, since it uses as much as digits as its factorization.

21017041 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 9170.

The product of its (nonzero) digits is 56, while the sum is 16.

The square root of 21017041 is about 4584.4346434430. The cubic root of 21017041 is about 275.9670241706.

Adding to 21017041 its reverse (14071012), we get a palindrome (35088053).

The spelling of 21017041 in words is "twenty-one million, seventeen thousand, forty-one".