1155123431 has 8 divisors (see below), whose sum is σ = 1440153984. Its totient is φ = 900096120.

The previous prime is 1155123413. The next prime is 1155123439. The reversal of 1155123431 is 1343215511.

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

It is not a de Polignac number, because 1155123431 - 2¹⁰ = 1155122407 is a prime.

It is a super-2 number, since 2×1155123431² = 2668620281690423522, which contains 22 as substring.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 1155123431.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1155123439) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 7500725 + ... + 7500878.

It is an arithmetic number, because the mean of its divisors is an integer number (180019248).

Almost surely, 2^1155123431 is an apocalyptic number.

1155123431 is a gapful number since it is divisible by the number (11) formed by its first and last digit.

1155123431 is a deficient number, since it is larger than the sum of its proper divisors (285030553).

1155123431 is a wasteful number, since it uses less digits than its factorization.

1155123431 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 15001621.

The product of its digits is 1800, while the sum is 26.

The square root of 1155123431 is about 33987.1068347984. The cubic root of 1155123431 is about 1049.2431222713.

Adding to 1155123431 its reverse (1343215511), we get a palindrome (2498338942).

The spelling of 1155123431 in words is "one billion, one hundred fifty-five million, one hundred twenty-three thousand, four hundred thirty-one".