161535413509 has 2 divisors, whose sum is σ = 161535413510. Its totient is φ = 161535413508.

The previous prime is 161535413447. The next prime is 161535413531. The reversal of 161535413509 is 905314535161.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 157553424900 + 3981988609 = 396930^2 + 63103^2 .

It is a cyclic number.

It is not a de Polignac number, because 161535413509 - 2¹¹ = 161535411461 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (161535416509) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 80767706754 + 80767706755.

It is an arithmetic number, because the mean of its divisors is an integer number (80767706755).

Almost surely, 2^161535413509 is an apocalyptic number.

It is an amenable number.

161535413509 is a deficient number, since it is larger than the sum of its proper divisors (1).

161535413509 is an equidigital number, since it uses as much as digits as its factorization.

161535413509 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 243000, while the sum is 43.

The spelling of 161535413509 in words is "one hundred sixty-one billion, five hundred thirty-five million, four hundred thirteen thousand, five hundred nine".