31302232131221 has 4 divisors (see below), whose sum is σ = 31418597306700. Its totient is φ = 31185866955744.

The previous prime is 31302232131173. The next prime is 31302232131227. The reversal of 31302232131221 is 12213123220313.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 11474038402225 + 19828193728996 = 3387335^2 + 4452886^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-31302232131221 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (31302232131227) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 58182587336 + ... + 58182587873.

It is an arithmetic number, because the mean of its divisors is an integer number (7854649326675).

Almost surely, 2^{31302232131221} is an apocalyptic number.

It is an amenable number.

31302232131221 is a deficient number, since it is larger than the sum of its proper divisors (116365175479).

31302232131221 is a wasteful number, since it uses less digits than its factorization.

31302232131221 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 116365175478.

The product of its (nonzero) digits is 2592, while the sum is 26.

Adding to 31302232131221 its reverse (12213123220313), we get a palindrome (43515355351534).

The spelling of 31302232131221 in words is "thirty-one trillion, three hundred two billion, two hundred thirty-two million, one hundred thirty-one thousand, two hundred twenty-one".