1685149657 has 2 divisors, whose sum is σ = 1685149658. Its totient is φ = 1685149656.

The previous prime is 1685149649. The next prime is 1685149699. The reversal of 1685149657 is 7569415861.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 1361905216 + 323244441 = 36904^2 + 17979^2 .

It is a cyclic number.

It is not a de Polignac number, because 1685149657 - 2³ = 1685149649 is a prime.

It is not a weakly prime, because it can be changed into another prime (1685149637) 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, 842574828 + 842574829.

It is an arithmetic number, because the mean of its divisors is an integer number (842574829).

Almost surely, 2^1685149657 is an apocalyptic number.

It is an amenable number.

1685149657 is a deficient number, since it is larger than the sum of its proper divisors (1).

1685149657 is an equidigital number, since it uses as much as digits as its factorization.

1685149657 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 1814400, while the sum is 52.

The square root of 1685149657 is about 41050.5743808780. The cubic root of 1685149657 is about 1189.9978007633.

The spelling of 1685149657 in words is "one billion, six hundred eighty-five million, one hundred forty-nine thousand, six hundred fifty-seven".