1685349666 has 320 divisors, whose sum is σ = 5347077120. Its totient is φ = 382112640.

The previous prime is 1685349623. The next prime is 1685349713. The reversal of 1685349666 is 6669435861.

It is a super-3 number, since 3×1685349666³ (a number of 29 digits) contains 333 as substring.

It is a Harshad number since it is a multiple of its sum of digits (54).

It is a Curzon number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 159 ways as a sum of consecutive naturals, for example, 3080805 + ... + 3081351.

It is an arithmetic number, because the mean of its divisors is an integer number (16709616).

Almost surely, 2^1685349666 is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 1685349666, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (2673538560).

1685349666 is an abundant number, since it is smaller than the sum of its proper divisors (3661727454).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

1685349666 is a wasteful number, since it uses less digits than its factorization.

1685349666 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 611 (or 602 counting only the distinct ones).

The product of its digits is 5598720, while the sum is 54.

The square root of 1685349666 is about 41053.0104377255. The cubic root of 1685349666 is about 1190.0448788479.

The spelling of 1685349666 in words is "one billion, six hundred eighty-five million, three hundred forty-nine thousand, six hundred sixty-six".