1999985 has 16 divisors (see below), whose sum is σ = 2676240.
Its totient is φ = 1424640.
The previous prime is 1999979. The next prime is 1999993. The reversal of 1999985 is 5899991.
It can be written as a sum of positive squares in 8 ways, for example, as 59536 + 1940449 = 244^2 + 1393^2
It is not a de Polignac number, because 1999985 - 24 = 1999969 is a prime.
It is a Curzon number.
It is a plaindrome in base 11.
It is a congruent number.
It is an unprimeable number.
It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 1355 + ... + 2415.
It is an arithmetic number, because the mean of its divisors is an integer number (167265).
21999985 is an apocalyptic number.
It is an amenable number.
1999985 is a deficient number, since it is larger than the sum of its proper divisors (676255).
1999985 is a wasteful number, since it uses less digits than its factorization.
1999985 is an evil number, because the sum of its binary digits is even.
The sum of its prime factors is 1108.
The product of its digits is 262440, while the sum is 50.
The square root of 1999985 is about 1414.2082590623.
The cubic root of 1999985 is about 125.9917900084.
The spelling of 1999985 in words is "one million, nine hundred ninety-nine thousand, nine hundred eighty-five".