1685707993 has 2 divisors, whose sum is σ = 1685707994. Its totient is φ = 1685707992.

The previous prime is 1685707967. The next prime is 1685708029. The reversal of 1685707993 is 3997075861.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 1059307209 + 626400784 = 32547^2 + 25028^2 .

It is a cyclic number.

It is not a de Polignac number, because 1685707993 - 2²⁵ = 1652153561 is a prime.

It is a super-2 number, since 2×1685707993² = 5683222875328176098, which contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (1685707963) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 842853996 + 842853997.

It is an arithmetic number, because the mean of its divisors is an integer number (842853997).

Almost surely, 2^1685707993 is an apocalyptic number.

It is an amenable number.

1685707993 is a deficient number, since it is larger than the sum of its proper divisors (1).

1685707993 is an equidigital number, since it uses as much as digits as its factorization.

1685707993 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 2857680, while the sum is 55.

The square root of 1685707993 is about 41057.3744046061. The cubic root of 1685707993 is about 1190.1292124835.

The spelling of 1685707993 in words is "one billion, six hundred eighty-five million, seven hundred seven thousand, nine hundred ninety-three".