1161012591 has 6 divisors (see below), whose sum is σ = 1677018200. Its totient is φ = 774008388.

The previous prime is 1161012581. The next prime is 1161012617. The reversal of 1161012591 is 1952101611.

1161012591 is a `hidden beast` number, since 1 + 1 + 61 + 0 + 12 + 591 = 666.

It is a de Polignac number, because none of the positive numbers 2^k-1161012591 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1161012571) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 64500691 + ... + 64500708.

Almost surely, 2^1161012591 is an apocalyptic number.

1161012591 is a deficient number, since it is larger than the sum of its proper divisors (516005609).

1161012591 is a wasteful number, since it uses less digits than its factorization.

1161012591 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 129001405 (or 129001402 counting only the distinct ones).

The product of its (nonzero) digits is 540, while the sum is 27.

The square root of 1161012591 is about 34073.6348369234. The cubic root of 1161012591 is about 1051.0232175239.

The spelling of 1161012591 in words is "one billion, one hundred sixty-one million, twelve thousand, five hundred ninety-one".