213131123031 has 4 divisors (see below), whose sum is σ = 284174830712. Its totient is φ = 142087415352.

The previous prime is 213131123017. The next prime is 213131123069. The reversal of 213131123031 is 130321131312.

It is a happy number.

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

It is not a de Polignac number, because 213131123031 - 2¹⁰ = 213131122007 is a prime.

It is a super-2 number, since 2×213131123031² (a number of 23 digits) contains 22 as substring.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 213131122989 and 213131123007.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (213131123071) 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 3 ways as a sum of consecutive naturals, for example, 35521853836 + ... + 35521853841.

It is an arithmetic number, because the mean of its divisors is an integer number (71043707678).

Almost surely, 2^213131123031 is an apocalyptic number.

213131123031 is a deficient number, since it is larger than the sum of its proper divisors (71043707681).

213131123031 is an equidigital number, since it uses as much as digits as its factorization.

213131123031 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 71043707680.

The product of its (nonzero) digits is 324, while the sum is 21.

Adding to 213131123031 its reverse (130321131312), we get a palindrome (343452254343).

The spelling of 213131123031 in words is "two hundred thirteen billion, one hundred thirty-one million, one hundred twenty-three thousand, thirty-one".