1155128215511 has 6 divisors (see below), whose sum is σ = 1219124238912. Its totient is φ = 1094331993300.

The previous prime is 1155128215489. The next prime is 1155128215519.

1155128215511 is nontrivially palindromic in base 10.

It is a de Polignac number, because none of the positive numbers 2^k-1155128215511 is a prime.

It is a super-2 number, since 2×1155128215511² (a number of 25 digits) contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1155128215519) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 1599900215 + ... + 1599900936.

It is an arithmetic number, because the mean of its divisors is an integer number (203187373152).

Almost surely, 2^{1155128215511} is an apocalyptic number.

1155128215511 is a deficient number, since it is larger than the sum of its proper divisors (63996023401).

1155128215511 is an equidigital number, since it uses as much as digits as its factorization.

1155128215511 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3199801189 (or 3199801170 counting only the distinct ones).

The product of its digits is 20000, while the sum is 38.

The spelling of 1155128215511 in words is "one trillion, one hundred fifty-five billion, one hundred twenty-eight million, two hundred fifteen thousand, five hundred eleven".