1151123231 has 4 divisors (see below), whose sum is σ = 1156150200. Its totient is φ = 1146096264.

The previous prime is 1151123179. The next prime is 1151123263. The reversal of 1151123231 is 1323211511.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-1151123231 is a prime.

It is a super-2 number, since 2×1151123231² = 2650169385895758722, which 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 (1151123291) 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, 2513141 + ... + 2513598.

It is an arithmetic number, because the mean of its divisors is an integer number (289037550).

Almost surely, 2^1151123231 is an apocalyptic number.

1151123231 is a deficient number, since it is larger than the sum of its proper divisors (5026969).

1151123231 is an equidigital number, since it uses as much as digits as its factorization.

1151123231 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5026968.

The product of its digits is 180, while the sum is 20.

The square root of 1151123231 is about 33928.2070112760. The cubic root of 1151123231 is about 1048.0305428694.

Adding to 1151123231 its reverse (1323211511), we get a palindrome (2474334742).

The spelling of 1151123231 in words is "one billion, one hundred fifty-one million, one hundred twenty-three thousand, two hundred thirty-one".