128784256815 has 16 divisors (see below), whose sum is σ = 212701741056. Its totient is φ = 66469293600.

The previous prime is 128784256807. The next prime is 128784256871. The reversal of 128784256815 is 518652487821.

It is not a de Polignac number, because 128784256815 - 2³ = 128784256807 is a prime.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 138477231 + ... + 138478160.

It is an arithmetic number, because the mean of its divisors is an integer number (13293858816).

Almost surely, 2^128784256815 is an apocalyptic number.

128784256815 is a gapful number since it is divisible by the number (15) formed by its first and last digit.

128784256815 is a deficient number, since it is larger than the sum of its proper divisors (83917484241).

128784256815 is a wasteful number, since it uses less digits than its factorization.

128784256815 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 276955430.

The product of its digits is 8601600, while the sum is 57.

The spelling of 128784256815 in words is "one hundred twenty-eight billion, seven hundred eighty-four million, two hundred fifty-six thousand, eight hundred fifteen".