1161111131 has 2 divisors, whose sum is σ = 1161111132. Its totient is φ = 1161111130.

The previous prime is 1161111113. The next prime is 1161111137. The reversal of 1161111131 is 1311111611.

Together with previous prime (1161111113) it forms an Ormiston pair, because they use the same digits, order apart.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 1161111131 - 2¹⁸ = 1160848987 is a prime.

It is a super-2 number, since 2×1161111131² = 2696358117064198322, which contains 22 as substring.

It is a Sophie Germain prime.

It is not a weakly prime, because it can be changed into another prime (1161111137) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 580555565 + 580555566.

It is an arithmetic number, because the mean of its divisors is an integer number (580555566).

Almost surely, 2^1161111131 is an apocalyptic number.

1161111131 is a deficient number, since it is larger than the sum of its proper divisors (1).

1161111131 is an equidigital number, since it uses as much as digits as its factorization.

1161111131 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 18, while the sum is 17.

The square root of 1161111131 is about 34075.0807922740. The cubic root of 1161111131 is about 1051.0529515965.

Adding to 1161111131 its reverse (1311111611), we get a palindrome (2472222742).

The spelling of 1161111131 in words is "one billion, one hundred sixty-one million, one hundred eleven thousand, one hundred thirty-one".