161809238741 has 2 divisors, whose sum is σ = 161809238742. Its totient is φ = 161809238740.

The previous prime is 161809238729. The next prime is 161809238803. The reversal of 161809238741 is 147832908161.

It is a happy number.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 158925011716 + 2884227025 = 398654^2 + 53705^2 .

It is a cyclic number.

It is not a de Polignac number, because 161809238741 - 2²² = 161805044437 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 161809238741.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (161809208741) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 80904619370 + 80904619371.

It is an arithmetic number, because the mean of its divisors is an integer number (80904619371).

Almost surely, 2^161809238741 is an apocalyptic number.

It is an amenable number.

161809238741 is a deficient number, since it is larger than the sum of its proper divisors (1).

161809238741 is an equidigital number, since it uses as much as digits as its factorization.

161809238741 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 580608, while the sum is 50.

The spelling of 161809238741 in words is "one hundred sixty-one billion, eight hundred nine million, two hundred thirty-eight thousand, seven hundred forty-one".