21001333013 has 4 divisors (see below), whose sum is σ = 21725516940. Its totient is φ = 20277149088.

The previous prime is 21001333009. The next prime is 21001333019. The reversal of 21001333013 is 31033310012.

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 5718686884 + 15282646129 = 75622^2 + 123623^2 .

It is a cyclic number.

It is not a de Polignac number, because 21001333013 - 2² = 21001333009 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 21001332982 and 21001333000.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21001333019) 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, 362091920 + ... + 362091977.

It is an arithmetic number, because the mean of its divisors is an integer number (5431379235).

Almost surely, 2^21001333013 is an apocalyptic number.

It is an amenable number.

21001333013 is a deficient number, since it is larger than the sum of its proper divisors (724183927).

21001333013 is an equidigital number, since it uses as much as digits as its factorization.

21001333013 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 724183926.

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

Adding to 21001333013 its reverse (31033310012), we get a palindrome (52034643025).

The spelling of 21001333013 in words is "twenty-one billion, one million, three hundred thirty-three thousand, thirteen".