31123221231 has 8 divisors (see below), whose sum is σ = 41513105920. Its totient is φ = 20741075352.

The previous prime is 31123221211. The next prime is 31123221251. The reversal of 31123221231 is 13212232113.

It is an interprime number because it is at equal distance from previous prime (31123221211) and next prime (31123221251).

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

It is not a de Polignac number, because 31123221231 - 2¹³ = 31123213039 is a prime.

It is a super-2 number, since 2×31123221231² (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 = 31123221198 and 31123221207.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (31123221211) 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 7 ways as a sum of consecutive naturals, for example, 1925311 + ... + 1941408.

It is an arithmetic number, because the mean of its divisors is an integer number (5189138240).

Almost surely, 2^31123221231 is an apocalyptic number.

31123221231 is a deficient number, since it is larger than the sum of its proper divisors (10389884689).

31123221231 is a wasteful number, since it uses less digits than its factorization.

31123221231 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3869405.

The product of its digits is 432, while the sum is 21.

Adding to 31123221231 its reverse (13212232113), we get a palindrome (44335453344).

The spelling of 31123221231 in words is "thirty-one billion, one hundred twenty-three million, two hundred twenty-one thousand, two hundred thirty-one".