1155251231 has 4 divisors (see below), whose sum is σ = 1166689464. Its totient is φ = 1143813000.

The previous prime is 1155251203. The next prime is 1155251233. The reversal of 1155251231 is 1321525511.

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-1155251231 is a prime.

It is a super-2 number, since 2×1155251231² = 2669210813454030722, 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 1155251231.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1155251233) 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, 5718965 + ... + 5719166.

It is an arithmetic number, because the mean of its divisors is an integer number (291672366).

Almost surely, 2^1155251231 is an apocalyptic number.

1155251231 is a deficient number, since it is larger than the sum of its proper divisors (11438233).

1155251231 is a wasteful number, since it uses less digits than its factorization.

1155251231 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 11438232.

The product of its digits is 1500, while the sum is 26.

The square root of 1155251231 is about 33988.9869075264. The cubic root of 1155251231 is about 1049.2818160658.

Adding to 1155251231 its reverse (1321525511), we get a palindrome (2476776742).

The spelling of 1155251231 in words is "one billion, one hundred fifty-five million, two hundred fifty-one thousand, two hundred thirty-one".