161605566657559 has 2 divisors, whose sum is σ = 161605566657560. Its totient is φ = 161605566657558.

The previous prime is 161605566657499. The next prime is 161605566657589. The reversal of 161605566657559 is 955756665506161.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 161605566657559 - 2²³ = 161605558268951 is a prime.

It is a super-2 number, since 2×161605566657559² (a number of 29 digits) contains 22 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 161605566657491 and 161605566657500.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (161605566657589) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 80802783328779 + 80802783328780.

It is an arithmetic number, because the mean of its divisors is an integer number (80802783328780).

Almost surely, 2^{161605566657559} is an apocalyptic number.

161605566657559 is a deficient number, since it is larger than the sum of its proper divisors (1).

161605566657559 is an equidigital number, since it uses as much as digits as its factorization.

161605566657559 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 1530900000, while the sum is 73.

The spelling of 161605566657559 in words is "one hundred sixty-one trillion, six hundred five billion, five hundred sixty-six million, six hundred fifty-seven thousand, five hundred fifty-nine".