1681487823816 has 320 divisors, whose sum is σ = 4870548144000. Its totient is φ = 541722746880.

The previous prime is 1681487823811. The next prime is 1681487823817. The reversal of 1681487823816 is 6183287841861.

It is a happy number.

1681487823816 is a `hidden beast` number, since 1 + 68 + 1 + 487 + 82 + 3 + 8 + 16 = 666.

It is not an unprimeable number, because it can be changed into a prime (1681487823811) by changing a digit.

It is a polite number, since it can be written in 79 ways as a sum of consecutive naturals, for example, 1381665640 + ... + 1381666856.

It is an arithmetic number, because the mean of its divisors is an integer number (15220462950).

Almost surely, 2^{1681487823816} 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 1681487823816, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (2435274072000).

1681487823816 is an abundant number, since it is smaller than the sum of its proper divisors (3189060320184).

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

1681487823816 is a wasteful number, since it uses less digits than its factorization.

1681487823816 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1874 (or 1861 counting only the distinct ones).

The product of its digits is 24772608, while the sum is 63.

The spelling of 1681487823816 in words is "one trillion, six hundred eighty-one billion, four hundred eighty-seven million, eight hundred twenty-three thousand, eight hundred sixteen".