213123312121231 has 4 divisors (see below), whose sum is σ = 213123515377032. Its totient is φ = 213123108865432.

The previous prime is 213123312121157. The next prime is 213123312121301. The reversal of 213123312121231 is 132121213321312.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 213123312121231 - 2⁴¹ = 210924288865679 is a prime.

It is a super-2 number, since 2×213123312121231² (a number of 29 digits) contains 22 as substring.

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 213123312121231.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (213123312131231) 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, 100046881 + ... + 102154906.

It is an arithmetic number, because the mean of its divisors is an integer number (53280878844258).

Almost surely, 2^{213123312121231} is an apocalyptic number.

213123312121231 is a deficient number, since it is larger than the sum of its proper divisors (203255801).

213123312121231 is a wasteful number, since it uses less digits than its factorization.

213123312121231 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 203255800.

The product of its digits is 2592, while the sum is 28.

Adding to 213123312121231 its reverse (132121213321312), we get a palindrome (345244525442543).

The spelling of 213123312121231 in words is "two hundred thirteen trillion, one hundred twenty-three billion, three hundred twelve million, one hundred twenty-one thousand, two hundred thirty-one".