1165605491 has 2 divisors, whose sum is σ = 1165605492. Its totient is φ = 1165605490.

The previous prime is 1165605479. The next prime is 1165605517. The reversal of 1165605491 is 1945065611.

It is a weak prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-1165605491 is a prime.

It is not a weakly prime, because it can be changed into another prime (1165635491) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 582802745 + 582802746.

It is an arithmetic number, because the mean of its divisors is an integer number (582802746).

Almost surely, 2^1165605491 is an apocalyptic number.

1165605491 is a deficient number, since it is larger than the sum of its proper divisors (1).

1165605491 is an equidigital number, since it uses as much as digits as its factorization.

1165605491 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 32400, while the sum is 38.

The square root of 1165605491 is about 34140.9649980782. The cubic root of 1165605491 is about 1052.4073234014.

The spelling of 1165605491 in words is "one billion, one hundred sixty-five million, six hundred five thousand, four hundred ninety-one".