161969 has 2 divisors, whose sum is σ = 161970. Its totient is φ = 161968.

The previous prime is 161957. The next prime is 161971. The reversal of 161969 is 969161.

It is a happy number.

161969 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 113569 + 48400 = 337^2 + 220^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-161969 is a prime.

It is a super-2 number, since 2×161969² = 52467913922, which contains 22 as substring.

Together with 161971, 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 (161999) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 80984 + 80985.

It is an arithmetic number, because the mean of its divisors is an integer number (80985).

2¹⁶¹⁹⁶⁹ is an apocalyptic number.

It is an amenable number.

161969 is a deficient number, since it is larger than the sum of its proper divisors (1).

161969 is an equidigital number, since it uses as much as digits as its factorization.

161969 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 2916, while the sum is 32.

The square root of 161969 is about 402.4537240479. The cubic root of 161969 is about 54.5101403571.

The spelling of 161969 in words is "one hundred sixty-one thousand, nine hundred sixty-nine".