21330041 has 4 divisors (see below), whose sum is σ = 21349284. Its totient is φ = 21310800.

The previous prime is 21329999. The next prime is 21330047. The reversal of 21330041 is 14003312.

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

It can be written as a sum of positive squares in 2 ways, for example, as 18524416 + 2805625 = 4304^2 + 1675^2 .

It is a cyclic number.

It is not a de Polignac number, because 21330041 - 2¹⁴ = 21313657 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is a junction number, because it is equal to n+sod(n) for n = 21329998 and 21330025.

It is not an unprimeable number, because it can be changed into a prime (21330047) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 7850 + ... + 10211.

It is an arithmetic number, because the mean of its divisors is an integer number (5337321).

Almost surely, 2^21330041 is an apocalyptic number.

It is an amenable number.

21330041 is a deficient number, since it is larger than the sum of its proper divisors (19243).

21330041 is a wasteful number, since it uses less digits than its factorization.

21330041 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 19242.

The product of its (nonzero) digits is 72, while the sum is 14.

The square root of 21330041 is about 4618.4457342270. The cubic root of 21330041 is about 277.3302416535.

Adding to 21330041 its reverse (14003312), we get a palindrome (35333353).

The spelling of 21330041 in words is "twenty-one million, three hundred thirty thousand, forty-one".