128654640 has 240 divisors, whose sum is σ = 478415808. Its totient is φ = 30818304.

The previous prime is 128654611. The next prime is 128654641. The reversal of 128654640 is 46456821.

128654640 is a `hidden beast` number, since 1 + 2 + 8 + 6 + 5 + 4 + 640 = 666.

It is a tau number, because it is divible by the number of its divisors (240).

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 = 128654595 and 128654604.

It is not an unprimeable number, because it can be changed into a prime (128654641) by changing a digit.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 281292 + ... + 281748.

Almost surely, 2^128654640 is an apocalyptic number.

128654640 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 128654640, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (239207904).

128654640 is an abundant number, since it is smaller than the sum of its proper divisors (349761168).

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

128654640 is a wasteful number, since it uses less digits than its factorization.

128654640 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 516 (or 507 counting only the distinct ones).

The product of its (nonzero) digits is 46080, while the sum is 36.

The square root of 128654640 is about 11342.6028758835. The cubic root of 128654640 is about 504.8261205773.

The spelling of 128654640 in words is "one hundred twenty-eight million, six hundred fifty-four thousand, six hundred forty".