31123205013 has 4 divisors (see below), whose sum is σ = 41497606688. Its totient is φ = 20748803340.

The previous prime is 31123204993. The next prime is 31123205033. The reversal of 31123205013 is 31050232113.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is an interprime number because it is at equal distance from previous prime (31123204993) and next prime (31123205033).

It is not a de Polignac number, because 31123205013 - 2⁹ = 31123204501 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 (31123205033) 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, 5187200833 + ... + 5187200838.

It is an arithmetic number, because the mean of its divisors is an integer number (10374401672).

Almost surely, 2^31123205013 is an apocalyptic number.

It is an amenable number.

31123205013 is a deficient number, since it is larger than the sum of its proper divisors (10374401675).

31123205013 is a wasteful number, since it uses less digits than its factorization.

31123205013 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 10374401674.

The product of its (nonzero) digits is 540, while the sum is 21.

Adding to 31123205013 its reverse (31050232113), we get a palindrome (62173437126).

The spelling of 31123205013 in words is "thirty-one billion, one hundred twenty-three million, two hundred five thousand, thirteen".