161668973 has 2 divisors, whose sum is σ = 161668974. Its totient is φ = 161668972.

The previous prime is 161668961. The next prime is 161669003. The reversal of 161668973 is 379866161.

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., 128640964 + 33028009 = 11342^2 + 5747^2 .

It is a cyclic number.

It is not a de Polignac number, because 161668973 - 2¹⁰ = 161667949 is a prime.

It is a super-2 number, since 2×161668973² = 52273713661749458, which contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (161668373) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 80834486 + 80834487.

It is an arithmetic number, because the mean of its divisors is an integer number (80834487).

Almost surely, 2^161668973 is an apocalyptic number.

It is an amenable number.

161668973 is a deficient number, since it is larger than the sum of its proper divisors (1).

161668973 is an equidigital number, since it uses as much as digits as its factorization.

161668973 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 326592, while the sum is 47.

The square root of 161668973 is about 12714.9114428690. The cubic root of 161668973 is about 544.7646184965.

The spelling of 161668973 in words is "one hundred sixty-one million, six hundred sixty-eight thousand, nine hundred seventy-three".