31210312121 has 8 divisors (see below), whose sum is σ = 33587955144. Its totient is φ = 28892862720.

The previous prime is 31210312109. The next prime is 31210312157. The reversal of 31210312121 is 12121301213.

It can be written as a sum of positive squares in 4 ways, for example, as 3442755625 + 27767556496 = 58675^2 + 166636^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 31210312121 - 2³⁰ = 30136570297 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (17).

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 31210312121.

It is not an unprimeable number, because it can be changed into a prime (31210312421) 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 7 ways as a sum of consecutive naturals, for example, 15047330 + ... + 15049403.

It is an arithmetic number, because the mean of its divisors is an integer number (4198494393).

Almost surely, 2^31210312121 is an apocalyptic number.

It is an amenable number.

31210312121 is a deficient number, since it is larger than the sum of its proper divisors (2377643023).

31210312121 is a wasteful number, since it uses less digits than its factorization.

31210312121 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 30096811.

The product of its (nonzero) digits is 72, while the sum is 17.

Adding to 31210312121 its reverse (12121301213), we get a palindrome (43331613334).

The spelling of 31210312121 in words is "thirty-one billion, two hundred ten million, three hundred twelve thousand, one hundred twenty-one".