1809916866 has 64 divisors (see below), whose sum is σ = 4272912000. Its totient is φ = 565913088.

The previous prime is 1809916811. The next prime is 1809916891. The reversal of 1809916866 is 6686199081.

It is a Harshad number since it is a multiple of its sum of digits (54).

It is an unprimeable number.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 284185 + ... + 290483.

It is an arithmetic number, because the mean of its divisors is an integer number (66764250).

Almost surely, 2^1809916866 is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 1809916866, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (2136456000).

1809916866 is an abundant number, since it is smaller than the sum of its proper divisors (2462995134).

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

1809916866 is a wasteful number, since it uses less digits than its factorization.

1809916866 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 6640 (or 6634 counting only the distinct ones).

The product of its (nonzero) digits is 1119744, while the sum is 54.

The square root of 1809916866 is about 42543.1177277830. The cubic root of 1809916866 is about 1218.6702491720.

The spelling of 1809916866 in words is "one billion, eight hundred nine million, nine hundred sixteen thousand, eight hundred sixty-six".