21001300123213 has 4 divisors (see below), whose sum is σ = 21397551068988. Its totient is φ = 20605049177440.

The previous prime is 21001300123183. The next prime is 21001300123229. The reversal of 21001300123213 is 31232100310012.

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 12573676299844 + 8427623823369 = 3545938^2 + 2903037^2 .

It is a cyclic number.

It is not a de Polignac number, because 21001300123213 - 2¹³ = 21001300115021 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 (21001300123273) 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, 198125472808 + ... + 198125472913.

It is an arithmetic number, because the mean of its divisors is an integer number (5349387767247).

Almost surely, 2^{21001300123213} is an apocalyptic number.

It is an amenable number.

21001300123213 is a deficient number, since it is larger than the sum of its proper divisors (396250945775).

21001300123213 is an equidigital number, since it uses as much as digits as its factorization.

21001300123213 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 396250945774.

The product of its (nonzero) digits is 216, while the sum is 19.

Adding to 21001300123213 its reverse (31232100310012), we get a palindrome (52233400433225).

The spelling of 21001300123213 in words is "twenty-one trillion, one billion, three hundred million, one hundred twenty-three thousand, two hundred thirteen".