213121203131021 has 16 divisors (see below), whose sum is σ = 217588835049984. Its totient is φ = 208670222464704.

The previous prime is 213121203131009. The next prime is 213121203131029. The reversal of 213121203131021 is 120131302121312.

It is a happy number.

It is not a de Polignac number, because 213121203131021 - 2¹⁰ = 213121203129997 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 (213121203131029) 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 15 ways as a sum of consecutive naturals, for example, 193400420 + ... + 194499266.

It is an arithmetic number, because the mean of its divisors is an integer number (13599302190624).

Almost surely, 2^{213121203131021} is an apocalyptic number.

It is an amenable number.

213121203131021 is a deficient number, since it is larger than the sum of its proper divisors (4467631918963).

213121203131021 is a wasteful number, since it uses less digits than its factorization.

213121203131021 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1106420.

The product of its (nonzero) digits is 432, while the sum is 23.

Adding to 213121203131021 its reverse (120131302121312), we get a palindrome (333252505252333).

The spelling of 213121203131021 in words is "two hundred thirteen trillion, one hundred twenty-one billion, two hundred three million, one hundred thirty-one thousand, twenty-one".