161507711509 has 2 divisors, whose sum is σ = 161507711510. Its totient is φ = 161507711508.

The previous prime is 161507711507. The next prime is 161507711531. The reversal of 161507711509 is 905117705161.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 138497855409 + 23009856100 = 372153^2 + 151690^2 .

It is an emirp because it is prime and its reverse (905117705161) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 161507711509 - 2¹ = 161507711507 is a prime.

Together with 161507711507, it forms a pair of twin primes.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (161507711507) 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, 80753855754 + 80753855755.

It is an arithmetic number, because the mean of its divisors is an integer number (80753855755).

Almost surely, 2^161507711509 is an apocalyptic number.

It is an amenable number.

161507711509 is a deficient number, since it is larger than the sum of its proper divisors (1).

161507711509 is an equidigital number, since it uses as much as digits as its factorization.

161507711509 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 66150, while the sum is 43.

The spelling of 161507711509 in words is "one hundred sixty-one billion, five hundred seven million, seven hundred eleven thousand, five hundred nine".