31233121 has 2 divisors, whose sum is σ = 31233122. Its totient is φ = 31233120.

The previous prime is 31233119. The next prime is 31233221. The reversal of 31233121 is 12133213.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 31136400 + 96721 = 5580^2 + 311^2 .

It is a cyclic number.

It is not a de Polignac number, because 31233121 - 2¹ = 31233119 is a prime.

Together with 31233119, it forms a pair of twin primes.

It is a junction number, because it is equal to n+sod(n) for n = 31233095 and 31233104.

It is not a weakly prime, because it can be changed into another prime (31233101) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 15616560 + 15616561.

It is an arithmetic number, because the mean of its divisors is an integer number (15616561).

Almost surely, 2^31233121 is an apocalyptic number.

It is an amenable number.

31233121 is a deficient number, since it is larger than the sum of its proper divisors (1).

31233121 is an equidigital number, since it uses as much as digits as its factorization.

31233121 is an evil number, because the sum of its binary digits is even.

The product of its digits is 108, while the sum is 16.

The square root of 31233121 is about 5588.6600361804. The cubic root of 31233121 is about 314.9235423741.

Adding to 31233121 its reverse (12133213), we get a palindrome (43366334).

It can be divided in two parts, 312 and 33121, that added together give a palindrome (33433).

The spelling of 31233121 in words is "thirty-one million, two hundred thirty-three thousand, one hundred twenty-one".