21421203213 has 4 divisors (see below), whose sum is σ = 28561604288. Its totient is φ = 14280802140.

The previous prime is 21421203197. The next prime is 21421203229. The reversal of 21421203213 is 31230212412.

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 an interprime number because it is at equal distance from previous prime (21421203197) and next prime (21421203229).

It is not a de Polignac number, because 21421203213 - 2⁴ = 21421203197 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 21421203213.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21421203263) 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, 3570200533 + ... + 3570200538.

It is an arithmetic number, because the mean of its divisors is an integer number (7140401072).

Almost surely, 2^21421203213 is an apocalyptic number.

It is an amenable number.

21421203213 is a deficient number, since it is larger than the sum of its proper divisors (7140401075).

21421203213 is an equidigital number, since it uses as much as digits as its factorization.

21421203213 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 7140401074.

The product of its (nonzero) digits is 576, while the sum is 21.

Adding to 21421203213 its reverse (31230212412), we get a palindrome (52651415625).

The spelling of 21421203213 in words is "twenty-one billion, four hundred twenty-one million, two hundred three thousand, two hundred thirteen".