161606729 has 2 divisors, whose sum is σ = 161606730. Its totient is φ = 161606728.

The previous prime is 161606719. The next prime is 161606791. The reversal of 161606729 is 927606161.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 135187129 + 26419600 = 11627^2 + 5140^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-161606729 is a prime.

It is a super-2 number, since 2×161606729² = 52233469716158882, which contains 22 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 161606692 and 161606701.

It is not a weakly prime, because it can be changed into another prime (161606719) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 80803364 + 80803365.

It is an arithmetic number, because the mean of its divisors is an integer number (80803365).

Almost surely, 2^161606729 is an apocalyptic number.

It is an amenable number.

161606729 is a deficient number, since it is larger than the sum of its proper divisors (1).

161606729 is an equidigital number, since it uses as much as digits as its factorization.

161606729 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 27216, while the sum is 38.

The square root of 161606729 is about 12712.4635299379. The cubic root of 161606729 is about 544.6946964393.

The spelling of 161606729 in words is "one hundred sixty-one million, six hundred six thousand, seven hundred twenty-nine".