31203203121 has 12 divisors (see below), whose sum is σ = 45073637700. Its totient is φ = 20801053440.

The previous prime is 31203203117. The next prime is 31203203137. The reversal of 31203203121 is 12130230213.

31203203121 is a `hidden beast` number, since 31 + 2 + 0 + 320 + 312 + 1 = 666.

It can be written as a sum of positive squares in 2 ways, for example, as 2408846400 + 28794356721 = 49080^2 + 169689^2 .

It is not a de Polignac number, because 31203203121 - 2² = 31203203117 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 31203203094 and 31203203103.

It is not an unprimeable number, because it can be changed into a prime (31203201121) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 117705 + ... + 276153.

It is an arithmetic number, because the mean of its divisors is an integer number (3756136475).

Almost surely, 2^31203203121 is an apocalyptic number.

It is an amenable number.

31203203121 is a deficient number, since it is larger than the sum of its proper divisors (13870434579).

31203203121 is a wasteful number, since it uses less digits than its factorization.

31203203121 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 180336 (or 180333 counting only the distinct ones).

The product of its (nonzero) digits is 216, while the sum is 18.

Adding to 31203203121 its reverse (12130230213), we get a palindrome (43333433334).

The spelling of 31203203121 in words is "thirty-one billion, two hundred three million, two hundred three thousand, one hundred twenty-one".