128540646 has 24 divisors (see below), whose sum is σ = 299928720. Its totient is φ = 39550896.

The previous prime is 128540641. The next prime is 128540651. The reversal of 128540646 is 646045821.

128540646 is a `hidden beast` number, since 1 + 2 + 8 + 5 + 4 + 0 + 646 = 666.

It is an interprime number because it is at equal distance from previous prime (128540641) and next prime (128540651).

It is a self number, because there is not a number n which added to its sum of digits gives 128540646.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (128540641) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 274426 + ... + 274893.

It is an arithmetic number, because the mean of its divisors is an integer number (12497030).

Almost surely, 2^128540646 is an apocalyptic number.

128540646 is an abundant number, since it is smaller than the sum of its proper divisors (171388074).

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

128540646 is a wasteful number, since it uses less digits than its factorization.

128540646 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 549340 (or 549337 counting only the distinct ones).

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

The square root of 128540646 is about 11337.5767252090. The cubic root of 128540646 is about 504.6769767049.

The spelling of 128540646 in words is "one hundred twenty-eight million, five hundred forty thousand, six hundred forty-six".