31030312321 has 4 divisors (see below), whose sum is σ = 31033167700. Its totient is φ = 31027456944.

The previous prime is 31030312273. The next prime is 31030312331. The reversal of 31030312321 is 12321303013.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 12321303013 = 421 ⋅29266753.

It can be written as a sum of positive squares in 2 ways, for example, as 3370963600 + 27659348721 = 58060^2 + 166311^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-31030312321 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (31030312331) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1411326 + ... + 1433143.

It is an arithmetic number, because the mean of its divisors is an integer number (7758291925).

Almost surely, 2^31030312321 is an apocalyptic number.

It is an amenable number.

31030312321 is a deficient number, since it is larger than the sum of its proper divisors (2855379).

31030312321 is a wasteful number, since it uses less digits than its factorization.

31030312321 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2855378.

The product of its (nonzero) digits is 324, while the sum is 19.

Adding to 31030312321 its reverse (12321303013), we get a palindrome (43351615334).

It can be divided in two parts, 310303 and 12321, that added together give a square (322624 = 568²).

The spelling of 31030312321 in words is "thirty-one billion, thirty million, three hundred twelve thousand, three hundred twenty-one".