31133121 has 4 divisors (see below), whose sum is σ = 41510832. Its totient is φ = 20755412.

The previous prime is 31133087. The next prime is 31133131. The reversal of 31133121 is 12133113.

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, and also an emirpimes, since its reverse is a distinct semiprime: 12133113 = 3 ⋅4044371.

It is a cyclic number.

It is not a de Polignac number, because 31133121 - 2¹⁰ = 31132097 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 31133121.

It is not an unprimeable number, because it can be changed into a prime (31133131) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 5188851 + ... + 5188856.

It is an arithmetic number, because the mean of its divisors is an integer number (10377708).

Almost surely, 2^31133121 is an apocalyptic number.

It is an amenable number.

31133121 is a deficient number, since it is larger than the sum of its proper divisors (10377711).

31133121 is a wasteful number, since it uses less digits than its factorization.

31133121 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 10377710.

The product of its digits is 54, while the sum is 15.

The square root of 31133121 is about 5579.7061750598. The cubic root of 31133121 is about 314.5870830520.

Adding to 31133121 its reverse (12133113), we get a palindrome (43266234).

The spelling of 31133121 in words is "thirty-one million, one hundred thirty-three thousand, one hundred twenty-one".