1181161691 has 2 divisors, whose sum is σ = 1181161692. Its totient is φ = 1181161690.

The previous prime is 1181161673. The next prime is 1181161697. The reversal of 1181161691 is 1961611811.

It is a strong prime.

It is an emirp because it is prime and its reverse (1961611811) is a distict prime. It is also a bemirp because it and its reverse can be mirrored producing other two distinct primes, 1691911811 and 1181191961.

It is a cyclic number.

It is not a de Polignac number, because 1181161691 - 2¹⁸ = 1180899547 is a prime.

It is not a weakly prime, because it can be changed into another prime (1181161697) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 590580845 + 590580846.

It is an arithmetic number, because the mean of its divisors is an integer number (590580846).

Almost surely, 2^1181161691 is an apocalyptic number.

1181161691 is a deficient number, since it is larger than the sum of its proper divisors (1).

1181161691 is an equidigital number, since it uses as much as digits as its factorization.

1181161691 is an evil number, because the sum of its binary digits is even.

The product of its digits is 2592, while the sum is 35.

The square root of 1181161691 is about 34368.0329812458. The cubic root of 1181161691 is about 1057.0684667235.

The spelling of 1181161691 in words is "one billion, one hundred eighty-one million, one hundred sixty-one thousand, six hundred ninety-one".