128773440 has 168 divisors, whose sum is σ = 450802248. Its totient is φ = 33730560.

The previous prime is 128773367. The next prime is 128773471. The reversal of 128773440 is 44377821.

It is a happy number.

It can be written as a sum of positive squares in 4 ways, for example, as 14197824 + 114575616 = 3768^2 + 10704^2 .

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 = 128773395 and 128773404.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 175314 + ... + 176046.

Almost surely, 2^128773440 is an apocalyptic number.

128773440 is a gapful number since it is divisible by the number (10) 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 128773440, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (225401124).

128773440 is an abundant number, since it is smaller than the sum of its proper divisors (322028808).

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

128773440 is a wasteful number, since it uses less digits than its factorization.

128773440 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 817 (or 804 counting only the distinct ones).

The product of its (nonzero) digits is 37632, while the sum is 36.

The square root of 128773440 is about 11347.8385607128. The cubic root of 128773440 is about 504.9814586533.

The spelling of 128773440 in words is "one hundred twenty-eight million, seven hundred seventy-three thousand, four hundred forty".