31131312103 has 4 divisors (see below), whose sum is σ = 31132366920. Its totient is φ = 31130257288.

The previous prime is 31131312097. The next prime is 31131312131. The reversal of 31131312103 is 30121313113.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 30121313113 = 5657 ⋅5324609.

It is a cyclic number.

It is not a de Polignac number, because 31131312103 - 2²¹ = 31129214951 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 (31131312143) 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, 481825 + ... + 542602.

It is an arithmetic number, because the mean of its divisors is an integer number (7783091730).

Almost surely, 2^31131312103 is an apocalyptic number.

31131312103 is a deficient number, since it is larger than the sum of its proper divisors (1054817).

31131312103 is a wasteful number, since it uses less digits than its factorization.

31131312103 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1054816.

The product of its (nonzero) digits is 162, while the sum is 19.

Adding to 31131312103 its reverse (30121313113), we get a palindrome (61252625216).

The spelling of 31131312103 in words is "thirty-one billion, one hundred thirty-one million, three hundred twelve thousand, one hundred three".