21013144871 has 2 divisors, whose sum is σ = 21013144872. Its totient is φ = 21013144870.

The previous prime is 21013144861. The next prime is 21013144903. The reversal of 21013144871 is 17844131012.

It is an a-pointer prime, because the next prime (21013144903) can be obtained adding 21013144871 to its sum of digits (32).

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 21013144871 - 2³⁴ = 3833275687 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21013144861) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10506572435 + 10506572436.

It is an arithmetic number, because the mean of its divisors is an integer number (10506572436).

Almost surely, 2^21013144871 is an apocalyptic number.

21013144871 is a deficient number, since it is larger than the sum of its proper divisors (1).

21013144871 is an equidigital number, since it uses as much as digits as its factorization.

21013144871 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 5376, while the sum is 32.

Adding to 21013144871 its reverse (17844131012), we get a palindrome (38857275883).

The spelling of 21013144871 in words is "twenty-one billion, thirteen million, one hundred forty-four thousand, eight hundred seventy-one".