20998000013 has 2 divisors, whose sum is σ = 20998000014. Its totient is φ = 20998000012.

The previous prime is 20997999991. The next prime is 20998000021. The reversal of 20998000013 is 31000089902.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 20995430404 + 2569609 = 144898^2 + 1603^2 .

It is a cyclic number.

It is not a de Polignac number, because 20998000013 - 2¹⁸ = 20997737869 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (20998000033) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10499000006 + 10499000007.

It is an arithmetic number, because the mean of its divisors is an integer number (10499000007).

Almost surely, 2^20998000013 is an apocalyptic number.

It is an amenable number.

20998000013 is a deficient number, since it is larger than the sum of its proper divisors (1).

20998000013 is an equidigital number, since it uses as much as digits as its factorization.

20998000013 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 3888, while the sum is 32.

Adding to 20998000013 its reverse (31000089902), we get a palindrome (51998089915).

The spelling of 20998000013 in words is "twenty billion, nine hundred ninety-eight million, thirteen", and thus it is an aban number.