1812364661844 has 288 divisors, whose sum is σ = 5202770227200. Its totient is φ = 527165210880.

The previous prime is 1812364661831. The next prime is 1812364661893. The reversal of 1812364661844 is 4481664632181.

1812364661844 is a `hidden beast` number, since 1 + 8 + 12 + 3 + 6 + 4 + 6 + 618 + 4 + 4 = 666.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 95 ways as a sum of consecutive naturals, for example, 534776902 + ... + 534780290.

It is an arithmetic number, because the mean of its divisors is an integer number (18065174400).

Almost surely, 2^{1812364661844} 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 1812364661844, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (2601385113600).

1812364661844 is an abundant number, since it is smaller than the sum of its proper divisors (3390405565356).

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

1812364661844 is a wasteful number, since it uses less digits than its factorization.

1812364661844 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4003 (or 3998 counting only the distinct ones).

The product of its digits is 5308416, while the sum is 54.

The spelling of 1812364661844 in words is "one trillion, eight hundred twelve billion, three hundred sixty-four million, six hundred sixty-one thousand, eight hundred forty-four".