31123203113 has 4 divisors (see below), whose sum is σ = 31124395008. Its totient is φ = 31122011220.

The previous prime is 31123203049. The next prime is 31123203121. The reversal of 31123203113 is 31130232113.

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 a cyclic number.

It is not a de Polignac number, because 31123203113 - 2⁶ = 31123203049 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (31123203193) 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, 555881 + ... + 609302.

It is an arithmetic number, because the mean of its divisors is an integer number (7781098752).

Almost surely, 2^31123203113 is an apocalyptic number.

It is an amenable number.

31123203113 is a deficient number, since it is larger than the sum of its proper divisors (1191895).

31123203113 is a wasteful number, since it uses less digits than its factorization.

31123203113 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1191894.

The product of its (nonzero) digits is 324, while the sum is 20.

Adding to 31123203113 its reverse (31130232113), we get a palindrome (62253435226).

The spelling of 31123203113 in words is "thirty-one billion, one hundred twenty-three million, two hundred three thousand, one hundred thirteen".