21044340571 has 2 divisors, whose sum is σ = 21044340572. Its totient is φ = 21044340570.

The previous prime is 21044340553. The next prime is 21044340599. The reversal of 21044340571 is 17504344012.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 21044340571 - 2⁵ = 21044340539 is a prime.

It is not a weakly prime, because it can be changed into another prime (21044340971) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10522170285 + 10522170286.

It is an arithmetic number, because the mean of its divisors is an integer number (10522170286).

Almost surely, 2^21044340571 is an apocalyptic number.

21044340571 is a deficient number, since it is larger than the sum of its proper divisors (1).

21044340571 is an equidigital number, since it uses as much as digits as its factorization.

21044340571 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 13440, while the sum is 31.

Adding to 21044340571 its reverse (17504344012), we get a palindrome (38548684583).

The spelling of 21044340571 in words is "twenty-one billion, forty-four million, three hundred forty thousand, five hundred seventy-one".