21004004443 has 2 divisors, whose sum is σ = 21004004444. Its totient is φ = 21004004442.

The previous prime is 21004004429. The next prime is 21004004467. The reversal of 21004004443 is 34440040012.

It is a weak prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-21004004443 is a prime.

It is not a weakly prime, because it can be changed into another prime (21004004143) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10502002221 + 10502002222.

It is an arithmetic number, because the mean of its divisors is an integer number (10502002222).

Almost surely, 2^21004004443 is an apocalyptic number.

21004004443 is a deficient number, since it is larger than the sum of its proper divisors (1).

21004004443 is an equidigital number, since it uses as much as digits as its factorization.

21004004443 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 1536, while the sum is 22.

Adding to 21004004443 its reverse (34440040012), we get a palindrome (55444044455).

The spelling of 21004004443 in words is "twenty-one billion, four million, four thousand, four hundred forty-three".