128776554 has 40 divisors (see below), whose sum is σ = 289795968. Its totient is φ = 42741000.

The previous prime is 128776553. The next prime is 128776561. The reversal of 128776554 is 455677821.

128776554 is a `hidden beast` number, since 1 + 28 + 7 + 76 + 554 = 666.

It is a super-2 number, since 2×128776554² = 33166801720229832, which contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (128776553) 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 19 ways as a sum of consecutive naturals, for example, 39079 + ... + 42245.

Almost surely, 2^128776554 is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 128776554, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (144897984).

128776554 is an abundant number, since it is smaller than the sum of its proper divisors (161019414).

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

128776554 is a wasteful number, since it uses less digits than its factorization.

128776554 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3432 (or 3423 counting only the distinct ones).

The product of its digits is 470400, while the sum is 45.

The square root of 128776554 is about 11347.9757666290. The cubic root of 128776554 is about 504.9855291086.

It can be divided in two parts, 1287 and 76554, that added together give a square (77841 = 279²).

The spelling of 128776554 in words is "one hundred twenty-eight million, seven hundred seventy-six thousand, five hundred fifty-four".