1686394397520 has 960 divisors, whose sum is σ = 6922472933376. Its totient is φ = 373479413760.

The previous prime is 1686394397507. The next prime is 1686394397543. The reversal of 1686394397520 is 257934936861.

1686394397520 is a `hidden beast` number, since 1 + 6 + 8 + 63 + 9 + 43 + 9 + 7 + 520 = 666.

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

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 191 ways as a sum of consecutive naturals, for example, 1545732175 + ... + 1545733265.

It is a 1-persistent number, because it is pandigital, but 2⋅1686394397520 = 3372788795040 is not.

Almost surely, 2^{1686394397520} is an apocalyptic number.

1686394397520 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 1686394397520, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (3461236466688).

1686394397520 is an abundant number, since it is smaller than the sum of its proper divisors (5236078535856).

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

1686394397520 is a wasteful number, since it uses less digits than its factorization.

1686394397520 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1470 (or 1452 counting only the distinct ones).

The product of its (nonzero) digits is 58786560, while the sum is 63.

The spelling of 1686394397520 in words is "one trillion, six hundred eighty-six billion, three hundred ninety-four million, three hundred ninety-seven thousand, five hundred twenty".