21641317013 has 4 divisors (see below), whose sum is σ = 21642811788. Its totient is φ = 21639822240.

The previous prime is 21641317001. The next prime is 21641317043. The reversal of 21641317013 is 31071314612.

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 3226012804 + 18415304209 = 56798^2 + 135703^2 .

It is a cyclic number.

It is not a de Polignac number, because 21641317013 - 2¹⁶ = 21641251477 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21641317043) 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, 725456 + ... + 754697.

It is an arithmetic number, because the mean of its divisors is an integer number (5410702947).

Almost surely, 2^21641317013 is an apocalyptic number.

It is an amenable number.

21641317013 is a deficient number, since it is larger than the sum of its proper divisors (1494775).

21641317013 is a wasteful number, since it uses less digits than its factorization.

21641317013 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1494774.

The product of its (nonzero) digits is 3024, while the sum is 29.

The spelling of 21641317013 in words is "twenty-one billion, six hundred forty-one million, three hundred seventeen thousand, thirteen".