21004402241 has 4 divisors (see below), whose sum is σ = 22239955332. Its totient is φ = 19768849152.

The previous prime is 21004402231. The next prime is 21004402261. The reversal of 21004402241 is 14220440012.

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 12522729025 + 8481673216 = 111905^2 + 92096^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-21004402241 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21004402231) 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, 617776520 + ... + 617776553.

It is an arithmetic number, because the mean of its divisors is an integer number (5559988833).

Almost surely, 2^21004402241 is an apocalyptic number.

It is an amenable number.

21004402241 is a deficient number, since it is larger than the sum of its proper divisors (1235553091).

21004402241 is a wasteful number, since it uses less digits than its factorization.

21004402241 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1235553090.

The product of its (nonzero) digits is 512, while the sum is 20.

Adding to 21004402241 its reverse (14220440012), we get a palindrome (35224842253).

The spelling of 21004402241 in words is "twenty-one billion, four million, four hundred two thousand, two hundred forty-one".