21004024441 has 2 divisors, whose sum is σ = 21004024442. Its totient is φ = 21004024440.

The previous prime is 21004024429. The next prime is 21004024451. The reversal of 21004024441 is 14442040012.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 18761054841 + 2242969600 = 136971^2 + 47360^2 .

It is a cyclic number.

It is not a de Polignac number, because 21004024441 - 2¹³ = 21004016249 is a prime.

It is not a weakly prime, because it can be changed into another prime (21004024451) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10502012220 + 10502012221.

It is an arithmetic number, because the mean of its divisors is an integer number (10502012221).

Almost surely, 2^21004024441 is an apocalyptic number.

It is an amenable number.

21004024441 is a deficient number, since it is larger than the sum of its proper divisors (1).

21004024441 is an equidigital number, since it uses as much as digits as its factorization.

21004024441 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 1024, while the sum is 22.

Adding to 21004024441 its reverse (14442040012), we get a palindrome (35446064453).

The spelling of 21004024441 in words is "twenty-one billion, four million, twenty-four thousand, four hundred forty-one".