31128113 has 4 divisors (see below), whose sum is σ = 31200768. Its totient is φ = 31055460.

The previous prime is 31128091. The next prime is 31128127. The reversal of 31128113 is 31182113.

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 a de Polignac number, because none of the positive numbers 2^k-31128113 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (31128193) 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, 35681 + ... + 36542.

It is an arithmetic number, because the mean of its divisors is an integer number (7800192).

Almost surely, 2^31128113 is an apocalyptic number.

It is an amenable number.

31128113 is a deficient number, since it is larger than the sum of its proper divisors (72655).

31128113 is an equidigital number, since it uses as much as digits as its factorization.

31128113 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 72654.

The product of its digits is 144, while the sum is 20.

The square root of 31128113 is about 5579.2573878609. The cubic root of 31128113 is about 314.5702142369.

The spelling of 31128113 in words is "thirty-one million, one hundred twenty-eight thousand, one hundred thirteen".