161734561 has 2 divisors, whose sum is σ = 161734562. Its totient is φ = 161734560.

The previous prime is 161734553. The next prime is 161734589. The reversal of 161734561 is 165437161.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 161163025 + 571536 = 12695^2 + 756^2 .

It is a cyclic number.

It is not a de Polignac number, because 161734561 - 2³ = 161734553 is a prime.

It is not a weakly prime, because it can be changed into another prime (161734501) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 80867280 + 80867281.

It is an arithmetic number, because the mean of its divisors is an integer number (80867281).

Almost surely, 2^161734561 is an apocalyptic number.

It is an amenable number.

161734561 is a deficient number, since it is larger than the sum of its proper divisors (1).

161734561 is an equidigital number, since it uses as much as digits as its factorization.

161734561 is an evil number, because the sum of its binary digits is even.

The product of its digits is 15120, while the sum is 34.

The square root of 161734561 is about 12717.4903577711. The cubic root of 161734561 is about 544.8382776335.

The spelling of 161734561 in words is "one hundred sixty-one million, seven hundred thirty-four thousand, five hundred sixty-one".