128681646 has 8 divisors (see below), whose sum is σ = 257363304. Its totient is φ = 42893880.

The previous prime is 128681639. The next prime is 128681659. The reversal of 128681646 is 646186821.

It is a sphenic number, since it is the product of 3 distinct primes.

128681646 is an admirable number.

It is a junction number, because it is equal to n+sod(n) for n = 128681598 and 128681607.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 10723465 + ... + 10723476.

It is an arithmetic number, because the mean of its divisors is an integer number (32170413).

Almost surely, 2^128681646 is an apocalyptic number.

128681646 is a primitive abundant number, since it is smaller than the sum of its proper divisors, none of which is abundant.

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

128681646 is a wasteful number, since it uses less digits than its factorization.

128681646 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 21446946.

The product of its digits is 110592, while the sum is 42.

The square root of 128681646 is about 11343.7932809092. The cubic root of 128681646 is about 504.8614409264.

The spelling of 128681646 in words is "one hundred twenty-eight million, six hundred eighty-one thousand, six hundred forty-six".