1685650217 has 2 divisors, whose sum is σ = 1685650218. Its totient is φ = 1685650216.

The previous prime is 1685650171. The next prime is 1685650223. The reversal of 1685650217 is 7120565861.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 1681902121 + 3748096 = 41011^2 + 1936^2 .

It is a cyclic number.

It is not a de Polignac number, because 1685650217 - 2¹² = 1685646121 is a prime.

It is not a weakly prime, because it can be changed into another prime (1685650247) 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, 842825108 + 842825109.

It is an arithmetic number, because the mean of its divisors is an integer number (842825109).

Almost surely, 2^1685650217 is an apocalyptic number.

It is an amenable number.

1685650217 is a deficient number, since it is larger than the sum of its proper divisors (1).

1685650217 is an equidigital number, since it uses as much as digits as its factorization.

1685650217 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 100800, while the sum is 41.

The square root of 1685650217 is about 41056.6707978131. The cubic root of 1685650217 is about 1190.1156154882.

The spelling of 1685650217 in words is "one billion, six hundred eighty-five million, six hundred fifty thousand, two hundred seventeen".