21000013303013 has 4 divisors (see below), whose sum is σ = 21049894570188. Its totient is φ = 20950132035840.

The previous prime is 21000013302971. The next prime is 21000013303021. The reversal of 21000013303013 is 31030331000012.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 5882987187169 + 15117026115844 = 2425487^2 + 3888062^2 .

It is a cyclic number.

It is not a de Polignac number, because 21000013303013 - 2⁴⁴ = 3407827258597 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 21000013302982 and 21000013303000.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21000013303813) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 24940632956 + ... + 24940633797.

It is an arithmetic number, because the mean of its divisors is an integer number (5262473642547).

Almost surely, 2^{21000013303013} is an apocalyptic number.

It is an amenable number.

21000013303013 is a deficient number, since it is larger than the sum of its proper divisors (49881267175).

21000013303013 is an equidigital number, since it uses as much as digits as its factorization.

21000013303013 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 49881267174.

The product of its (nonzero) digits is 162, while the sum is 17.

Adding to 21000013303013 its reverse (31030331000012), we get a palindrome (52030344303025).

The spelling of 21000013303013 in words is "twenty-one trillion, thirteen million, three hundred three thousand, thirteen".