21073437013 has 4 divisors (see below), whose sum is σ = 21111963040. Its totient is φ = 21034910988.

The previous prime is 21073436983. The next prime is 21073437071. The reversal of 21073437013 is 31073437012.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-21073437013 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21073437713) 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, 19262193 + ... + 19263286.

It is an arithmetic number, because the mean of its divisors is an integer number (5277990760).

Almost surely, 2^21073437013 is an apocalyptic number.

It is an amenable number.

21073437013 is a deficient number, since it is larger than the sum of its proper divisors (38526027).

21073437013 is an equidigital number, since it uses as much as digits as its factorization.

21073437013 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 38526026.

The product of its (nonzero) digits is 10584, while the sum is 31.

Subtracting 21073437013 from its reverse (31073437012), we obtain a palindrome (9999999999).

The spelling of 21073437013 in words is "twenty-one billion, seventy-three million, four hundred thirty-seven thousand, thirteen".