1645873 has 2 divisors, whose sum is σ = 1645874. Its totient is φ = 1645872.

The previous prime is 1645867. The next prime is 1645879. The reversal of 1645873 is 3785461.

It is a balanced prime because it is at equal distance from previous prime (1645867) and next prime (1645879).

It can be written as a sum of positive squares in only one way, i.e., 1617984 + 27889 = 1272^2 + 167^2 .

It is a cyclic number.

It is not a de Polignac number, because 1645873 - 2¹⁷ = 1514801 is a prime.

It is not a weakly prime, because it can be changed into another prime (1645879) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 822936 + 822937.

It is an arithmetic number, because the mean of its divisors is an integer number (822937).

2^1645873 is an apocalyptic number.

It is an amenable number.

1645873 is a deficient number, since it is larger than the sum of its proper divisors (1).

1645873 is an equidigital number, since it uses as much as digits as its factorization.

1645873 is an evil number, because the sum of its binary digits is even.

The product of its digits is 20160, while the sum is 34.

The square root of 1645873 is about 1282.9158195299. The cubic root of 1645873 is about 118.0679729028.

The spelling of 1645873 in words is "one million, six hundred forty-five thousand, eight hundred seventy-three".