161073821 has 2 divisors, whose sum is σ = 161073822. Its totient is φ = 161073820.

The previous prime is 161073797. The next prime is 161073851. The reversal of 161073821 is 128370161.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 125193721 + 35880100 = 11189^2 + 5990^2 .

It is a cyclic number.

It is not a de Polignac number, because 161073821 - 2¹⁴ = 161057437 is a prime.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (161073851) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 80536910 + 80536911.

It is an arithmetic number, because the mean of its divisors is an integer number (80536911).

Almost surely, 2^161073821 is an apocalyptic number.

It is an amenable number.

161073821 is a deficient number, since it is larger than the sum of its proper divisors (1).

161073821 is an equidigital number, since it uses as much as digits as its factorization.

161073821 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 2016, while the sum is 29.

The square root of 161073821 is about 12691.4861619906. The cubic root of 161073821 is about 544.0953158478.

The spelling of 161073821 in words is "one hundred sixty-one million, seventy-three thousand, eight hundred twenty-one".