1209328128 has 240 divisors, whose sum is σ = 3693185496. Its totient is φ = 380436480.

The previous prime is 1209328123. The next prime is 1209328171. The reversal of 1209328128 is 8218239021.

1209328128 is a `hidden beast` number, since 1 + 209 + 328 + 128 = 666.

It can be written as a sum of positive squares in 4 ways, for example, as 1158177024 + 51151104 = 34032^2 + 7152^2 .

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

It is a junction number, because it is equal to n+sod(n) for n = 1209328092 and 1209328101.

It is not an unprimeable number, because it can be changed into a prime (1209328123) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 6990250 + ... + 6990422.

Almost surely, 2^1209328128 is an apocalyptic number.

1209328128 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 1209328128, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1846592748).

1209328128 is an abundant number, since it is smaller than the sum of its proper divisors (2483857368).

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

1209328128 is a wasteful number, since it uses less digits than its factorization.

1209328128 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 275 (or 256 counting only the distinct ones).

The product of its (nonzero) digits is 13824, while the sum is 36.

The square root of 1209328128 is about 34775.3954398796. The cubic root of 1209328128 is about 1065.4049693118.

The spelling of 1209328128 in words is "one billion, two hundred nine million, three hundred twenty-eight thousand, one hundred twenty-eight".