1816856835840 has 576 divisors, whose sum is σ = 6835011724800. Its totient is φ = 455432011776.

The previous prime is 1816856835817. The next prime is 1816856835841. The reversal of 1816856835840 is 485386586181.

1816856835840 is a `hidden beast` number, since 1 + 8 + 1 + 68 + 568 + 3 + 5 + 8 + 4 + 0 = 666.

It is a tau number, because it is divible by the number of its divisors (576).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1816856835841) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 63 ways as a sum of consecutive naturals, for example, 683284431 + ... + 683287089.

It is an arithmetic number, because the mean of its divisors is an integer number (11866339800).

Almost surely, 2^{1816856835840} is an apocalyptic number.

1816856835840 is a gapful number since it is divisible by the number (10) 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 1816856835840, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (3417505862400).

1816856835840 is an abundant number, since it is smaller than the sum of its proper divisors (5018154888960).

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

1816856835840 is a wasteful number, since it uses less digits than its factorization.

1816856835840 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3869 (or 3849 counting only the distinct ones).

The product of its (nonzero) digits is 44236800, while the sum is 63.

The spelling of 1816856835840 in words is "one trillion, eight hundred sixteen billion, eight hundred fifty-six million, eight hundred thirty-five thousand, eight hundred forty".