31545215209 has 2 divisors, whose sum is σ = 31545215210. Its totient is φ = 31545215208.

The previous prime is 31545215179. The next prime is 31545215237. The reversal of 31545215209 is 90251254513.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 30567277225 + 977937984 = 174835^2 + 31272^2 .

It is a cyclic number.

It is not a de Polignac number, because 31545215209 - 2⁹ = 31545214697 is a prime.

It is not a weakly prime, because it can be changed into another prime (31545210209) 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 as a sum of consecutive naturals, namely, 15772607604 + 15772607605.

It is an arithmetic number, because the mean of its divisors is an integer number (15772607605).

Almost surely, 2^31545215209 is an apocalyptic number.

It is an amenable number.

31545215209 is a deficient number, since it is larger than the sum of its proper divisors (1).

31545215209 is an equidigital number, since it uses as much as digits as its factorization.

31545215209 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 54000, while the sum is 37.

The spelling of 31545215209 in words is "thirty-one billion, five hundred forty-five million, two hundred fifteen thousand, two hundred nine".