161398709 has 2 divisors, whose sum is σ = 161398710. Its totient is φ = 161398708.

The previous prime is 161398687. The next prime is 161398723. The reversal of 161398709 is 907893161.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 161213809 + 184900 = 12697^2 + 430^2 .

It is a cyclic number.

It is not a de Polignac number, because 161398709 - 2¹⁶ = 161333173 is a prime.

It is a Chen prime.

It is a self number, because there is not a number n which added to its sum of digits gives 161398709.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (161398739) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 80699354 + 80699355.

It is an arithmetic number, because the mean of its divisors is an integer number (80699355).

Almost surely, 2^161398709 is an apocalyptic number.

It is an amenable number.

161398709 is a deficient number, since it is larger than the sum of its proper divisors (1).

161398709 is an equidigital number, since it uses as much as digits as its factorization.

161398709 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 81648, while the sum is 44.

The square root of 161398709 is about 12704.2791609756. The cubic root of 161398709 is about 544.4608859567.

The spelling of 161398709 in words is "one hundred sixty-one million, three hundred ninety-eight thousand, seven hundred nine".