128666772 has 96 divisors (see below), whose sum is σ = 362866560. Its totient is φ = 39191040.

The previous prime is 128666753. The next prime is 128666789. The reversal of 128666772 is 277666821.

It is a zygodrome in base 3.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 158247 + ... + 159057.

It is an arithmetic number, because the mean of its divisors is an integer number (3779860).

Almost surely, 2^128666772 is an apocalyptic number.

128666772 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 128666772, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (181433280).

128666772 is an abundant number, since it is smaller than the sum of its proper divisors (234199788).

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

128666772 is a wasteful number, since it uses less digits than its factorization.

128666772 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 950 (or 942 counting only the distinct ones).

The product of its digits is 338688, while the sum is 45.

The square root of 128666772 is about 11343.1376611588. The cubic root of 128666772 is about 504.8419882729.

The spelling of 128666772 in words is "one hundred twenty-eight million, six hundred sixty-six thousand, seven hundred seventy-two".