31089397993 has 2 divisors, whose sum is σ = 31089397994. Its totient is φ = 31089397992.

The previous prime is 31089397981. The next prime is 31089398047. The reversal of 31089397993 is 39979398013.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 23226674409 + 7862723584 = 152403^2 + 88672^2 .

It is a cyclic number.

It is not a de Polignac number, because 31089397993 - 2¹³ = 31089389801 is a prime.

It is not a weakly prime, because it can be changed into another prime (31089397903) 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 as a sum of consecutive naturals, namely, 15544698996 + 15544698997.

It is an arithmetic number, because the mean of its divisors is an integer number (15544698997).

Almost surely, 2^31089397993 is an apocalyptic number.

It is an amenable number.

31089397993 is a deficient number, since it is larger than the sum of its proper divisors (1).

31089397993 is an equidigital number, since it uses as much as digits as its factorization.

31089397993 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 9920232, while the sum is 61.

The spelling of 31089397993 in words is "thirty-one billion, eighty-nine million, three hundred ninety-seven thousand, nine hundred ninety-three".