1691685305856 has 1800 divisors, whose sum is σ = 6629328289584. Its totient is φ = 420267294720.

The previous prime is 1691685305837. The next prime is 1691685305867. The reversal of 1691685305856 is 6585035861961.

1691685305856 is a `hidden beast` number, since 1 + 6 + 9 + 16 + 8 + 5 + 30 + 585 + 6 = 666.

It is a Harshad number since it is a multiple of its sum of digits (63).

It is a junction number, because it is equal to n+sod(n) for n = 1691685305793 and 1691685305802.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 179 ways as a sum of consecutive naturals, for example, 41260617196 + ... + 41260617236.

Almost surely, 2^{1691685305856} is an apocalyptic number.

1691685305856 is a gapful number since it is divisible by the number (16) 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 1691685305856, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (3314664144792).

1691685305856 is an abundant number, since it is smaller than the sum of its proper divisors (4937642983728).

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

1691685305856 is an equidigital number, since it uses as much as digits as its factorization.

1691685305856 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 162 (or 95 counting only the distinct ones).

The product of its (nonzero) digits is 46656000, while the sum is 63.

The spelling of 1691685305856 in words is "one trillion, six hundred ninety-one billion, six hundred eighty-five million, three hundred five thousand, eight hundred fifty-six".