1685951849 has 4 divisors (see below), whose sum is σ = 1686993540. Its totient is φ = 1684910160.

The previous prime is 1685951821. The next prime is 1685951867. The reversal of 1685951849 is 9481595861.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 793436224 + 892515625 = 28168^2 + 29875^2 .

It is a cyclic number.

It is not a de Polignac number, because 1685951849 - 2¹⁶ = 1685886313 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is a junction number, because it is equal to n+sod(n) for n = 1685951794 and 1685951803.

It is not an unprimeable number, because it can be changed into a prime (1685951249) 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 in 3 ways as a sum of consecutive naturals, for example, 518414 + ... + 521655.

It is an arithmetic number, because the mean of its divisors is an integer number (421748385).

Almost surely, 2^1685951849 is an apocalyptic number.

It is an amenable number.

1685951849 is a deficient number, since it is larger than the sum of its proper divisors (1041691).

1685951849 is a wasteful number, since it uses less digits than its factorization.

1685951849 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1041690.

The product of its digits is 3110400, while the sum is 56.

The square root of 1685951849 is about 41060.3439951494. The cubic root of 1685951849 is about 1190.1865980958.

The spelling of 1685951849 in words is "one billion, six hundred eighty-five million, nine hundred fifty-one thousand, eight hundred forty-nine".