1089405991 has 2 divisors, whose sum is σ = 1089405992. Its totient is φ = 1089405990.

The previous prime is 1089405949. The next prime is 1089406001. The reversal of 1089405991 is 1995049801.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 1089405991 - 2¹⁷ = 1089274919 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (1089405931) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 544702995 + 544702996.

It is an arithmetic number, because the mean of its divisors is an integer number (544702996).

Almost surely, 2^1089405991 is an apocalyptic number.

1089405991 is a deficient number, since it is larger than the sum of its proper divisors (1).

1089405991 is an equidigital number, since it uses as much as digits as its factorization.

1089405991 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 116640, while the sum is 46.

The square root of 1089405991 is about 33006.1508055696. The cubic root of 1089405991 is about 1028.9554846235.

The spelling of 1089405991 in words is "one billion, eighty-nine million, four hundred five thousand, nine hundred ninety-one".