1985109867 has 48 divisors (see below), whose sum is σ = 3141989760. Its totient is φ = 1200386304.

The previous prime is 1985109851. The next prime is 1985109869. The reversal of 1985109867 is 7689015891.

It is not a de Polignac number, because 1985109867 - 2⁴ = 1985109851 is a prime.

It is a super-2 number, since 2×1985109867² = 7881322368121515378, which contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (1985109869) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 2707833 + ... + 2708565.

It is an arithmetic number, because the mean of its divisors is an integer number (65458120).

Almost surely, 2^1985109867 is an apocalyptic number.

1985109867 is a deficient number, since it is larger than the sum of its proper divisors (1156879893).

1985109867 is a wasteful number, since it uses less digits than its factorization.

1985109867 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1124 (or 1121 counting only the distinct ones).

The product of its (nonzero) digits is 1088640, while the sum is 54.

The square root of 1985109867 is about 44554.5717856204. The cubic root of 1985109867 is about 1256.7865260636.

The spelling of 1985109867 in words is "one billion, nine hundred eighty-five million, one hundred nine thousand, eight hundred sixty-seven".