128957640 has 64 divisors (see below), whose sum is σ = 442143360. Its totient is φ = 29475840.

The previous prime is 128957623. The next prime is 128957641. The reversal of 128957640 is 46759821.

It is a Harshad number since it is a multiple of its sum of digits (42).

It is a junction number, because it is equal to n+sod(n) for n = 128957592 and 128957601.

It is not an unprimeable number, because it can be changed into a prime (128957641) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 75921 + ... + 77600.

It is an arithmetic number, because the mean of its divisors is an integer number (6908490).

Almost surely, 2^128957640 is an apocalyptic number.

128957640 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

128957640 is an abundant number, since it is smaller than the sum of its proper divisors (313185720).

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

128957640 is a wasteful number, since it uses less digits than its factorization.

128957640 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 153542 (or 153538 counting only the distinct ones).

The product of its (nonzero) digits is 120960, while the sum is 42.

The square root of 128957640 is about 11355.9517434691. The cubic root of 128957640 is about 505.2221223298. Note that the first 3 decimals are identical.

The spelling of 128957640 in words is "one hundred twenty-eight million, nine hundred fifty-seven thousand, six hundred forty".