1165987591 has 2 divisors, whose sum is σ = 1165987592. Its totient is φ = 1165987590.

The previous prime is 1165987583. The next prime is 1165987607. The reversal of 1165987591 is 1957895611.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 1165987591 - 2³ = 1165987583 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (1165087591) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 582993795 + 582993796.

It is an arithmetic number, because the mean of its divisors is an integer number (582993796).

Almost surely, 2^1165987591 is an apocalyptic number.

1165987591 is a deficient number, since it is larger than the sum of its proper divisors (1).

1165987591 is an equidigital number, since it uses as much as digits as its factorization.

1165987591 is an evil number, because the sum of its binary digits is even.

The product of its digits is 680400, while the sum is 52.

The square root of 1165987591 is about 34146.5604563622. The cubic root of 1165987591 is about 1052.5223082481.

The spelling of 1165987591 in words is "one billion, one hundred sixty-five million, nine hundred eighty-seven thousand, five hundred ninety-one".