21071724313 has 2 divisors, whose sum is σ = 21071724314. Its totient is φ = 21071724312.

The previous prime is 21071724301. The next prime is 21071724361. The reversal of 21071724313 is 31342717012.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 13982589504 + 7089134809 = 118248^2 + 84197^2 .

It is a cyclic number.

It is not a de Polignac number, because 21071724313 - 2⁹ = 21071723801 is a prime.

It is not a weakly prime, because it can be changed into another prime (21071724613) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10535862156 + 10535862157.

It is an arithmetic number, because the mean of its divisors is an integer number (10535862157).

Almost surely, 2^21071724313 is an apocalyptic number.

It is an amenable number.

21071724313 is a deficient number, since it is larger than the sum of its proper divisors (1).

21071724313 is an equidigital number, since it uses as much as digits as its factorization.

21071724313 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 7056, while the sum is 31.

The spelling of 21071724313 in words is "twenty-one billion, seventy-one million, seven hundred twenty-four thousand, three hundred thirteen".