1011085991 has 2 divisors, whose sum is σ = 1011085992. Its totient is φ = 1011085990.

The previous prime is 1011085849. The next prime is 1011086039. The reversal of 1011085991 is 1995801101.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 1011085991 - 2²⁶ = 943977127 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (1011085391) 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 as a sum of consecutive naturals, namely, 505542995 + 505542996.

It is an arithmetic number, because the mean of its divisors is an integer number (505542996).

Almost surely, 2^1011085991 is an apocalyptic number.

1011085991 is a deficient number, since it is larger than the sum of its proper divisors (1).

1011085991 is an equidigital number, since it uses as much as digits as its factorization.

1011085991 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 3240, while the sum is 35.

The square root of 1011085991 is about 31797.5783826379. The cubic root of 1011085991 is about 1003.6817583529.

The spelling of 1011085991 in words is "one billion, eleven million, eighty-five thousand, nine hundred ninety-one".