31020312321 has 12 divisors (see below), whose sum is σ = 45054673300. Its totient is φ = 20565951840.

The previous prime is 31020312319. The next prime is 31020312353. The reversal of 31020312321 is 12321302013.

31020312321 is a `hidden beast` number, since 3 + 10 + 20 + 312 + 321 = 666.

It can be written as a sum of positive squares in 2 ways, for example, as 5078700225 + 25941612096 = 71265^2 + 161064^2 .

It is not a de Polignac number, because 31020312321 - 2¹ = 31020312319 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 31020312294 and 31020312303.

It is not an unprimeable number, because it can be changed into a prime (31020312121) 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, 9519646 + ... + 9522903.

Almost surely, 2^31020312321 is an apocalyptic number.

It is an amenable number.

31020312321 is a deficient number, since it is larger than the sum of its proper divisors (14034360979).

31020312321 is a wasteful number, since it uses less digits than its factorization.

31020312321 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 19042736 (or 19042733 counting only the distinct ones).

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

Adding to 31020312321 its reverse (12321302013), we get a palindrome (43341614334).

The spelling of 31020312321 in words is "thirty-one billion, twenty million, three hundred twelve thousand, three hundred twenty-one".