1680206569 has 2 divisors, whose sum is σ = 1680206570. Its totient is φ = 1680206568.

The previous prime is 1680206513. The next prime is 1680206579. The reversal of 1680206569 is 9656020861.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 1553936400 + 126270169 = 39420^2 + 11237^2 .

It is a cyclic number.

It is not a de Polignac number, because 1680206569 - 2⁹ = 1680206057 is a prime.

It is a super-2 number, since 2×1680206569² = 5646188229021503522, which contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (1680206579) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 840103284 + 840103285.

It is an arithmetic number, because the mean of its divisors is an integer number (840103285).

Almost surely, 2^1680206569 is an apocalyptic number.

It is an amenable number.

1680206569 is a deficient number, since it is larger than the sum of its proper divisors (1).

1680206569 is an equidigital number, since it uses as much as digits as its factorization.

1680206569 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 155520, while the sum is 43.

The square root of 1680206569 is about 40990.3228701605. The cubic root of 1680206569 is about 1188.8331119690.

The spelling of 1680206569 in words is "one billion, six hundred eighty million, two hundred six thousand, five hundred sixty-nine".