128428551 has 8 divisors (see below), whose sum is σ = 190264560. Its totient is φ = 85619016.

The previous prime is 128428549. The next prime is 128428561. The reversal of 128428551 is 155824821.

128428551 is a `hidden beast` number, since 1 + 2 + 84 + 28 + 551 = 666.

It is not a de Polignac number, because 128428551 - 2¹ = 128428549 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (128428541) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 2378280 + ... + 2378333.

It is an arithmetic number, because the mean of its divisors is an integer number (23783070).

Almost surely, 2^128428551 is an apocalyptic number.

128428551 is a deficient number, since it is larger than the sum of its proper divisors (61836009).

128428551 is an equidigital number, since it uses as much as digits as its factorization.

128428551 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4756622 (or 4756616 counting only the distinct ones).

The product of its digits is 25600, while the sum is 36.

The square root of 128428551 is about 11332.6321302688. The cubic root of 128428551 is about 504.5302313755.

The spelling of 128428551 in words is "one hundred twenty-eight million, four hundred twenty-eight thousand, five hundred fifty-one".