31123210231 has 4 divisors (see below), whose sum is σ = 31260317112. Its totient is φ = 30986103352.

The previous prime is 31123210201. The next prime is 31123210259. The reversal of 31123210231 is 13201232113.

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 31123210231 - 2¹³ = 31123202039 is a prime.

It is a super-2 number, since 2×31123210231² (a number of 22 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 = 31123210199 and 31123210208.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (31123210201) 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, 68553100 + ... + 68553553.

It is an arithmetic number, because the mean of its divisors is an integer number (7815079278).

Almost surely, 2^31123210231 is an apocalyptic number.

31123210231 is a deficient number, since it is larger than the sum of its proper divisors (137106881).

31123210231 is a wasteful number, since it uses less digits than its factorization.

31123210231 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 137106880.

The product of its (nonzero) digits is 216, while the sum is 19.

Adding to 31123210231 its reverse (13201232113), we get a palindrome (44324442344).

The spelling of 31123210231 in words is "thirty-one billion, one hundred twenty-three million, two hundred ten thousand, two hundred thirty-one".