1645743161 has 2 divisors, whose sum is σ = 1645743162. Its totient is φ = 1645743160.

The previous prime is 1645743067. The next prime is 1645743179. The reversal of 1645743161 is 1613475461.

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., 1609213225 + 36529936 = 40115^2 + 6044^2 .

It is a cyclic number.

It is not a de Polignac number, because 1645743161 - 2¹⁴ = 1645726777 is a prime.

It is not a weakly prime, because it can be changed into another prime (1645743061) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 822871580 + 822871581.

It is an arithmetic number, because the mean of its divisors is an integer number (822871581).

Almost surely, 2^1645743161 is an apocalyptic number.

It is an amenable number.

1645743161 is a deficient number, since it is larger than the sum of its proper divisors (1).

1645743161 is an equidigital number, since it uses as much as digits as its factorization.

1645743161 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 60480, while the sum is 38.

The square root of 1645743161 is about 40567.7601181036. The cubic root of 1645743161 is about 1180.6486812075.

The spelling of 1645743161 in words is "one billion, six hundred forty-five million, seven hundred forty-three thousand, one hundred sixty-one".