1686688128 has 96 divisors (see below), whose sum is σ = 4908454200. Its totient is φ = 555878400.

The previous prime is 1686688109. The next prime is 1686688147. The reversal of 1686688128 is 8218866861.

It is an interprime number because it is at equal distance from previous prime (1686688109) and next prime (1686688147).

It is a tau number, because it is divible by the number of its divisors (96).

It is a super-2 number, since 2×1686688128² = 5689833682272288768, which contains 22 as substring.

It is a Smith number, since the sum of its digits (54) coincides with the sum of the digits of its prime factors.

It is a nude number because it is divisible by every one of its digits.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 94303 + ... + 110753.

Almost surely, 2^1686688128 is an apocalyptic number.

1686688128 is a gapful number since it is divisible by the number (18) 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 1686688128, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (2454227100).

1686688128 is an abundant number, since it is smaller than the sum of its proper divisors (3221766072).

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

1686688128 is a wasteful number, since it uses less digits than its factorization.

1686688128 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 16560 (or 16545 counting only the distinct ones).

The product of its digits is 1769472, while the sum is 54.

The square root of 1686688128 is about 41069.3088327525. The cubic root of 1686688128 is about 1190.3598299834.

The spelling of 1686688128 in words is "one billion, six hundred eighty-six million, six hundred eighty-eight thousand, one hundred twenty-eight".