128697440 has 48 divisors (see below), whose sum is σ = 308357280. Its totient is φ = 50749440.

The previous prime is 128697427. The next prime is 128697449. The reversal of 128697440 is 44796821.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (128697449) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 5696 + ... + 17024.

It is an arithmetic number, because the mean of its divisors is an integer number (6424110).

Almost surely, 2^128697440 is an apocalyptic number.

128697440 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 128697440, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (154178640).

128697440 is an abundant number, since it is smaller than the sum of its proper divisors (179659840).

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

128697440 is a wasteful number, since it uses less digits than its factorization.

128697440 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 11415 (or 11407 counting only the distinct ones).

The product of its (nonzero) digits is 96768, while the sum is 41.

The square root of 128697440 is about 11344.4894111635. The cubic root of 128697440 is about 504.8820951420.

The spelling of 128697440 in words is "one hundred twenty-eight million, six hundred ninety-seven thousand, four hundred forty".