128109816 has 128 divisors (see below), whose sum is σ = 376358400. Its totient is φ = 40296960.

The previous prime is 128109811. The next prime is 128109823. The reversal of 128109816 is 618901821.

It is a Harshad number since it is a multiple of its sum of digits (36).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (128109811) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 531456 + ... + 531696.

It is an arithmetic number, because the mean of its divisors is an integer number (2940300).

Almost surely, 2^128109816 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 128109816, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (188179200).

128109816 is an abundant number, since it is smaller than the sum of its proper divisors (248248584).

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

128109816 is a wasteful number, since it uses less digits than its factorization.

128109816 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 386 (or 376 counting only the distinct ones).

The product of its (nonzero) digits is 6912, while the sum is 36.

The square root of 128109816 is about 11318.5606858823. The cubic root of 128109816 is about 504.1125032298.

The spelling of 128109816 in words is "one hundred twenty-eight million, one hundred nine thousand, eight hundred sixteen".