21071471513 has 2 divisors, whose sum is σ = 21071471514. Its totient is φ = 21071471512.

The previous prime is 21071471501. The next prime is 21071471539. The reversal of 21071471513 is 31517417012.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 13198103689 + 7873367824 = 114883^2 + 88732^2 .

It is a cyclic number.

It is not a de Polignac number, because 21071471513 - 2¹⁶ = 21071405977 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 21071471513.

It is not a weakly prime, because it can be changed into another prime (21071461513) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10535735756 + 10535735757.

It is an arithmetic number, because the mean of its divisors is an integer number (10535735757).

Almost surely, 2^21071471513 is an apocalyptic number.

It is an amenable number.

21071471513 is a deficient number, since it is larger than the sum of its proper divisors (1).

21071471513 is an equidigital number, since it uses as much as digits as its factorization.

21071471513 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 5880, while the sum is 32.

Adding to 21071471513 its reverse (31517417012), we get a palindrome (52588888525).

The spelling of 21071471513 in words is "twenty-one billion, seventy-one million, four hundred seventy-one thousand, five hundred thirteen".