1809814644 has 96 divisors (see below), whose sum is σ = 5176483200. Its totient is φ = 542234880.

The previous prime is 1809814631. The next prime is 1809814697. The reversal of 1809814644 is 4464189081.

1809814644 is a `hidden beast` number, since 180 + 9 + 8 + 1 + 464 + 4 = 666.

It is a self number, because there is not a number n which added to its sum of digits gives 1809814644.

It is a congruent number.

It is an unprimeable number.

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 31 ways as a sum of consecutive naturals, for example, 97174 + ... + 114290.

It is an arithmetic number, because the mean of its divisors is an integer number (53921700).

Almost surely, 2^1809814644 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 1809814644, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (2588241600).

1809814644 is an abundant number, since it is smaller than the sum of its proper divisors (3366668556).

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

1809814644 is a wasteful number, since it uses less digits than its factorization.

1809814644 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 17230 (or 17222 counting only the distinct ones).

The product of its (nonzero) digits is 221184, while the sum is 45.

The square root of 1809814644 is about 42541.9163179093. The cubic root of 1809814644 is about 1218.6473057139.

The spelling of 1809814644 in words is "one billion, eight hundred nine million, eight hundred fourteen thousand, six hundred forty-four".