21143231244413 has 4 divisors (see below), whose sum is σ = 21330339485628. Its totient is φ = 20956123003200.

The previous prime is 21143231244407. The next prime is 21143231244461. The reversal of 21143231244413 is 31444213234112.

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 5972930705764 + 15170300538649 = 2443958^2 + 3894907^2 .

It is a cyclic number.

It is not a de Polignac number, because 21143231244413 - 2²⁰ = 21143230195837 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 (21143231244313) 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, 93554120438 + ... + 93554120663.

It is an arithmetic number, because the mean of its divisors is an integer number (5332584871407).

Almost surely, 2^{21143231244413} is an apocalyptic number.

It is an amenable number.

21143231244413 is a deficient number, since it is larger than the sum of its proper divisors (187108241215).

21143231244413 is a wasteful number, since it uses less digits than its factorization.

21143231244413 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 187108241214.

The product of its digits is 55296, while the sum is 35.

Adding to 21143231244413 its reverse (31444213234112), we get a palindrome (52587444478525).

The spelling of 21143231244413 in words is "twenty-one trillion, one hundred forty-three billion, two hundred thirty-one million, two hundred forty-four thousand, four hundred thirteen".