1155123131 has 4 divisors (see below), whose sum is σ = 1155206664. Its totient is φ = 1155039600.

The previous prime is 1155123103. The next prime is 1155123133. The reversal of 1155123131 is 1313215511.

It is a semiprime because it is the product of two primes, and also a brilliant number, because the two primes have the same length, and also an emirpimes, since its reverse is a distinct semiprime: 1313215511 = 23813 ⋅55147.

It is a cyclic number.

It is not a de Polignac number, because 1155123131 - 2²² = 1150928827 is a prime.

It is a super-2 number, since 2×1155123131² = 2668618895542486322, which contains 22 as substring.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 1155123097 and 1155123106.

It is not an unprimeable number, because it can be changed into a prime (1155123133) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 15530 + ... + 50511.

It is an arithmetic number, because the mean of its divisors is an integer number (288801666).

Almost surely, 2^1155123131 is an apocalyptic number.

1155123131 is a deficient number, since it is larger than the sum of its proper divisors (83533).

1155123131 is an equidigital number, since it uses as much as digits as its factorization.

1155123131 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 83532.

The product of its digits is 450, while the sum is 23.

The square root of 1155123131 is about 33987.1024213598. The cubic root of 1155123131 is about 1049.2430314374.

Adding to 1155123131 its reverse (1313215511), we get a palindrome (2468338642).

The spelling of 1155123131 in words is "one billion, one hundred fifty-five million, one hundred twenty-three thousand, one hundred thirty-one".