1806521195556 has 576 divisors, whose sum is σ = 6393124864000. Its totient is φ = 430177651200.

The previous prime is 1806521195551. The next prime is 1806521195569. The reversal of 1806521195556 is 6555911256081.

1806521195556 is a `hidden beast` number, since 1 + 8 + 0 + 6 + 521 + 19 + 55 + 56 = 666.

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

It is not an unprimeable number, because it can be changed into a prime (1806521195551) 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 191 ways as a sum of consecutive naturals, for example, 53862600 + ... + 53896128.

Almost surely, 2^{1806521195556} 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 1806521195556, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (3196562432000).

1806521195556 is an abundant number, since it is smaller than the sum of its proper divisors (4586603668444).

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

1806521195556 is a wasteful number, since it uses less digits than its factorization.

1806521195556 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 33621 (or 33602 counting only the distinct ones).

The product of its (nonzero) digits is 3240000, while the sum is 54.

The spelling of 1806521195556 in words is "one trillion, eight hundred six billion, five hundred twenty-one million, one hundred ninety-five thousand, five hundred fifty-six".