1681686601812 has 384 divisors, whose sum is σ = 5369669222400. Its totient is φ = 444423687552.

The previous prime is 1681686601783. The next prime is 1681686601841. The reversal of 1681686601812 is 2181066861861.

1681686601812 is a `hidden beast` number, since 1 + 6 + 8 + 16 + 8 + 6 + 601 + 8 + 12 = 666.

It is an interprime number because it is at equal distance from previous prime (1681686601783) and next prime (1681686601841).

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

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 127 ways as a sum of consecutive naturals, for example, 299070033 + ... + 299075655.

It is an arithmetic number, because the mean of its divisors is an integer number (13983513600).

Almost surely, 2^{1681686601812} is an apocalyptic number.

1681686601812 is a gapful number since it is divisible by the number (12) 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 1681686601812, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (2684834611200).

1681686601812 is an abundant number, since it is smaller than the sum of its proper divisors (3687982620588).

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

1681686601812 is a wasteful number, since it uses less digits than its factorization.

1681686601812 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 6152 (or 6144 counting only the distinct ones).

The product of its (nonzero) digits is 1327104, while the sum is 54.

The spelling of 1681686601812 in words is "one trillion, six hundred eighty-one billion, six hundred eighty-six million, six hundred one thousand, eight hundred twelve".