1985985 has 32 divisors (see below), whose sum is σ = 3617280. Its totient is φ = 1033344.

The previous prime is 1985939. The next prime is 1985987. The reversal of 1985985 is 5895891.

It is not a de Polignac number, because 1985985 - 2⁸ = 1985729 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (45).

It is an Ulam number.

It is a self number, because there is not a number n which added to its sum of digits gives 1985985.

It is not an unprimeable number, because it can be changed into a prime (1985987) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 6189 + ... + 6501.

It is an arithmetic number, because the mean of its divisors is an integer number (113040).

2^1985985 is an apocalyptic number.

1985985 is a gapful number since it is divisible by the number (15) formed by its first and last digit.

1985985 is the 705-th decagonal number.

It is an amenable number.

1985985 is a deficient number, since it is larger than the sum of its proper divisors (1631295).

1985985 is a wasteful number, since it uses less digits than its factorization.

1985985 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 374 (or 368 counting only the distinct ones).

The product of its digits is 129600, while the sum is 45.

The square root of 1985985 is about 1409.2498004257. The cubic root of 1985985 is about 125.6971183144.

It can be divided in two parts, 198 and 5985, that multiplied together give a triangular number (1185030 = T₁₅₃₉).

The spelling of 1985985 in words is "one million, nine hundred eighty-five thousand, nine hundred eighty-five".