161450711561 has 2 divisors, whose sum is σ = 161450711562. Its totient is φ = 161450711560.

The previous prime is 161450711551. The next prime is 161450711563. The reversal of 161450711561 is 165117054161.

It is a happy number.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 115977708025 + 45473003536 = 340555^2 + 213244^2 .

It is a cyclic number.

It is not a de Polignac number, because 161450711561 - 2¹⁸ = 161450449417 is a prime.

Together with 161450711563, it forms a pair of twin primes.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (161450711563) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 80725355780 + 80725355781.

It is an arithmetic number, because the mean of its divisors is an integer number (80725355781).

Almost surely, 2^161450711561 is an apocalyptic number.

It is an amenable number.

161450711561 is a deficient number, since it is larger than the sum of its proper divisors (1).

161450711561 is an equidigital number, since it uses as much as digits as its factorization.

161450711561 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 25200, while the sum is 38.

The spelling of 161450711561 in words is "one hundred sixty-one billion, four hundred fifty million, seven hundred eleven thousand, five hundred sixty-one".