31305320509 has 2 divisors, whose sum is σ = 31305320510. Its totient is φ = 31305320508.

The previous prime is 31305320471. The next prime is 31305320521. The reversal of 31305320509 is 90502350313.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 29378988409 + 1926332100 = 171403^2 + 43890^2 .

It is an emirp because it is prime and its reverse (90502350313) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 31305320509 - 2³¹ = 29157836861 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (31305320609) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 15652660254 + 15652660255.

It is an arithmetic number, because the mean of its divisors is an integer number (15652660255).

Almost surely, 2^31305320509 is an apocalyptic number.

It is an amenable number.

31305320509 is a deficient number, since it is larger than the sum of its proper divisors (1).

31305320509 is an equidigital number, since it uses as much as digits as its factorization.

31305320509 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 12150, while the sum is 31.

The spelling of 31305320509 in words is "thirty-one billion, three hundred five million, three hundred twenty thousand, five hundred nine".