21202021013 has 4 divisors (see below), whose sum is σ = 21202367520. Its totient is φ = 21201674508.

The previous prime is 21202020971. The next prime is 21202021039. The reversal of 21202021013 is 31012020212.

It is a happy number.

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 not a de Polignac number, because 21202021013 - 2¹² = 21202016917 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 (21202021913) 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, 54203 + ... + 212936.

It is an arithmetic number, because the mean of its divisors is an integer number (5300591880).

Almost surely, 2^21202021013 is an apocalyptic number.

It is an amenable number.

21202021013 is a deficient number, since it is larger than the sum of its proper divisors (346507).

21202021013 is an equidigital number, since it uses as much as digits as its factorization.

21202021013 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 346506.

The product of its (nonzero) digits is 48, while the sum is 14.

Adding to 21202021013 its reverse (31012020212), we get a palindrome (52214041225).

The spelling of 21202021013 in words is "twenty-one billion, two hundred two million, twenty-one thousand, thirteen".