1151131231 has 4 divisors (see below), whose sum is σ = 1151383072. Its totient is φ = 1150879392.

The previous prime is 1151131229. The next prime is 1151131253. The reversal of 1151131231 is 1321311511.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 1321311511 = 13 ⋅101639347.

It is a cyclic number.

It is not a de Polignac number, because 1151131231 - 2¹ = 1151131229 is a prime.

It is a super-2 number, since 2×1151131231² = 2650206221967150722, 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 = 1151131199 and 1151131208.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1151131271) 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, 118935 + ... + 128248.

It is an arithmetic number, because the mean of its divisors is an integer number (287845768).

Almost surely, 2^1151131231 is an apocalyptic number.

1151131231 is a deficient number, since it is larger than the sum of its proper divisors (251841).

1151131231 is an equidigital number, since it uses as much as digits as its factorization.

1151131231 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 251840.

The product of its digits is 90, while the sum is 19.

The square root of 1151131231 is about 33928.3249070743. The cubic root of 1151131231 is about 1048.0329707082.

Adding to 1151131231 its reverse (1321311511), we get a palindrome (2472442742).

The spelling of 1151131231 in words is "one billion, one hundred fifty-one million, one hundred thirty-one thousand, two hundred thirty-one".