161091569 has 2 divisors, whose sum is σ = 161091570. Its totient is φ = 161091568.

The previous prime is 161091547. The next prime is 161091571. The reversal of 161091569 is 965190161.

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., 119617969 + 41473600 = 10937^2 + 6440^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-161091569 is a prime.

It is a super-2 number, since 2×161091569² = 51900987205763522, which contains 22 as substring.

Together with 161091571, 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 (161091529) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 80545784 + 80545785.

It is an arithmetic number, because the mean of its divisors is an integer number (80545785).

Almost surely, 2^161091569 is an apocalyptic number.

It is an amenable number.

161091569 is a deficient number, since it is larger than the sum of its proper divisors (1).

161091569 is an equidigital number, since it uses as much as digits as its factorization.

161091569 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 14580, while the sum is 38.

The square root of 161091569 is about 12692.1853516248. The cubic root of 161091569 is about 544.1152989193.

The spelling of 161091569 in words is "one hundred sixty-one million, ninety-one thousand, five hundred sixty-nine".