128831721155 has 16 divisors (see below), whose sum is σ = 155658547584. Its totient is φ = 102360792960.

The previous prime is 128831721121. The next prime is 128831721173. The reversal of 128831721155 is 551127138821.

It is a de Polignac number, because none of the positive numbers 2^k-128831721155 is a prime.

It is a super-2 number, since 2×128831721155² (a number of 23 digits) contains 22 as substring.

It is a Duffinian number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 279569 + ... + 579501.

It is an arithmetic number, because the mean of its divisors is an integer number (9728659224).

Almost surely, 2^128831721155 is an apocalyptic number.

128831721155 is a deficient number, since it is larger than the sum of its proper divisors (26826826429).

128831721155 is a wasteful number, since it uses less digits than its factorization.

128831721155 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 300526.

The product of its digits is 134400, while the sum is 44.

Adding to 128831721155 its reverse (551127138821), we get a palindrome (679958859976).

The spelling of 128831721155 in words is "one hundred twenty-eight billion, eight hundred thirty-one million, seven hundred twenty-one thousand, one hundred fifty-five".