1681455716820 has 192 divisors, whose sum is σ = 5778997862400. Its totient is φ = 402465697920.

The previous prime is 1681455716819. The next prime is 1681455716827. The reversal of 1681455716820 is 286175541861.

1681455716820 is a `hidden beast` number, since 1 + 6 + 8 + 1 + 4 + 5 + 571 + 68 + 2 + 0 = 666.

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

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1681455716827) by changing a digit.

It is a polite number, since it can be written in 63 ways as a sum of consecutive naturals, for example, 1322344 + ... + 2260863.

It is an arithmetic number, because the mean of its divisors is an integer number (30098947200).

Almost surely, 2^{1681455716820} is an apocalyptic number.

1681455716820 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

1681455716820 is an abundant number, since it is smaller than the sum of its proper divisors (4097542145580).

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

1681455716820 is a wasteful number, since it uses less digits than its factorization.

1681455716820 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3583315 (or 3583307 counting only the distinct ones).

The product of its (nonzero) digits is 3225600, while the sum is 54.

The spelling of 1681455716820 in words is "one trillion, six hundred eighty-one billion, four hundred fifty-five million, seven hundred sixteen thousand, eight hundred twenty".