21420423233213 has 4 divisors (see below), whose sum is σ = 21771577712508. Its totient is φ = 21069268753920.

The previous prime is 21420423233203. The next prime is 21420423233327. The reversal of 21420423233213 is 31233232402412.

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 9652964314084 + 11767458919129 = 3106922^2 + 3430373^2 .

It is a cyclic number.

It is not a de Polignac number, because 21420423233213 - 2¹⁶ = 21420423167677 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 21420423233213.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21420423233203) 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, 175577239556 + ... + 175577239677.

It is an arithmetic number, because the mean of its divisors is an integer number (5442894428127).

Almost surely, 2^{21420423233213} is an apocalyptic number.

It is an amenable number.

21420423233213 is a deficient number, since it is larger than the sum of its proper divisors (351154479295).

21420423233213 is an equidigital number, since it uses as much as digits as its factorization.

21420423233213 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 351154479294.

The product of its (nonzero) digits is 41472, while the sum is 32.

Adding to 21420423233213 its reverse (31233232402412), we get a palindrome (52653655635625).

The spelling of 21420423233213 in words is "twenty-one trillion, four hundred twenty billion, four hundred twenty-three million, two hundred thirty-three thousand, two hundred thirteen".