21021120010213 has 4 divisors (see below), whose sum is σ = 22257656481420. Its totient is φ = 19784583539008.

The previous prime is 21021120010199. The next prime is 21021120010243. The reversal of 21021120010213 is 31201002112012.

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 16487635887009 + 4533484123204 = 4060497^2 + 2129198^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-21021120010213 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 (21021120010243) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 618268235578 + ... + 618268235611.

It is an arithmetic number, because the mean of its divisors is an integer number (5564414120355).

Almost surely, 2^{21021120010213} is an apocalyptic number.

It is an amenable number.

21021120010213 is a deficient number, since it is larger than the sum of its proper divisors (1236536471207).

21021120010213 is a wasteful number, since it uses less digits than its factorization.

21021120010213 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1236536471206.

The product of its (nonzero) digits is 48, while the sum is 16.

Adding to 21021120010213 its reverse (31201002112012), we get a palindrome (52222122122225).

The spelling of 21021120010213 in words is "twenty-one trillion, twenty-one billion, one hundred twenty million, ten thousand, two hundred thirteen".