128781551 has 8 divisors (see below), whose sum is σ = 131868864. Its totient is φ = 125708800.

The previous prime is 128781509. The next prime is 128781589. The reversal of 128781551 is 155187821.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 128781551 - 2¹⁰ = 128780527 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (128781151) 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 7 ways as a sum of consecutive naturals, for example, 15431 + ... + 22263.

It is an arithmetic number, because the mean of its divisors is an integer number (16483608).

Almost surely, 2^128781551 is an apocalyptic number.

128781551 is a deficient number, since it is larger than the sum of its proper divisors (3087313).

128781551 is an equidigital number, since it uses as much as digits as its factorization.

128781551 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 7281.

The product of its digits is 22400, while the sum is 38.

The square root of 128781551 is about 11348.1959359186. The cubic root of 128781551 is about 504.9920607842.

The spelling of 128781551 in words is "one hundred twenty-eight million, seven hundred eighty-one thousand, five hundred fifty-one".