1865985912 has 96 divisors (see below), whose sum is σ = 5861980800. Its totient is φ = 525172032.

The previous prime is 1865985899. The next prime is 1865985917. The reversal of 1865985912 is 2195895681.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1865985917) 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 23 ways as a sum of consecutive naturals, for example, 6139 + ... + 61397.

It is an arithmetic number, because the mean of its divisors is an integer number (61062300).

Almost surely, 2^1865985912 is an apocalyptic number.

1865985912 is a gapful number since it is divisible by the number (12) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 1865985912, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (2930990400).

1865985912 is an abundant number, since it is smaller than the sum of its proper divisors (3995994888).

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

1865985912 is a wasteful number, since it uses less digits than its factorization.

1865985912 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 55345 (or 55338 counting only the distinct ones).

The product of its digits is 1555200, while the sum is 54.

The square root of 1865985912 is about 43197.0590665615. The cubic root of 1865985912 is about 1231.1268040239.

It can be divided in two parts, 186598 and 5912, that added together give a triangular number (192510 = T₆₂₀).

The spelling of 1865985912 in words is "one billion, eight hundred sixty-five million, nine hundred eighty-five thousand, nine hundred twelve".