31123032109 has 4 divisors (see below), whose sum is σ = 33517111516. Its totient is φ = 28728952704.

The previous prime is 31123032091. The next prime is 31123032139. The reversal of 31123032109 is 90123032113.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 90123032113 = 5861 ⋅15376733.

It can be written as a sum of positive squares in 2 ways, for example, as 3692385225 + 27430646884 = 60765^2 + 165622^2 .

It is a cyclic number.

It is not a de Polignac number, because 31123032109 - 2⁵ = 31123032077 is a prime.

It is a super-3 number, since 3×31123032109³ (a number of 32 digits) contains 333 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (31123032139) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1197039684 + ... + 1197039709.

It is an arithmetic number, because the mean of its divisors is an integer number (8379277879).

Almost surely, 2^31123032109 is an apocalyptic number.

It is an amenable number.

31123032109 is a deficient number, since it is larger than the sum of its proper divisors (2394079407).

31123032109 is a wasteful number, since it uses less digits than its factorization.

31123032109 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2394079406.

The product of its (nonzero) digits is 972, while the sum is 25.

The spelling of 31123032109 in words is "thirty-one billion, one hundred twenty-three million, thirty-two thousand, one hundred nine".