21204231213 has 8 divisors (see below), whose sum is σ = 30842518176. Its totient is φ = 12851049200.

The previous prime is 21204231187. The next prime is 21204231241. The reversal of 21204231213 is 31213240212.

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 21204231213 - 2¹⁰ = 21204230189 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 21204231213.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21204231313) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 321276198 + ... + 321276263.

It is an arithmetic number, because the mean of its divisors is an integer number (3855314772).

Almost surely, 2^21204231213 is an apocalyptic number.

It is an amenable number.

21204231213 is a deficient number, since it is larger than the sum of its proper divisors (9638286963).

21204231213 is a wasteful number, since it uses less digits than its factorization.

21204231213 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 642552475.

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

Adding to 21204231213 its reverse (31213240212), we get a palindrome (52417471425).

The spelling of 21204231213 in words is "twenty-one billion, two hundred four million, two hundred thirty-one thousand, two hundred thirteen".