1085564809 has 4 divisors (see below), whose sum is σ = 1240645504. Its totient is φ = 930484116.

The previous prime is 1085564807. The next prime is 1085564813. The reversal of 1085564809 is 9084655801.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 1085564809 - 2¹ = 1085564807 is a prime.

It is not an unprimeable number, because it can be changed into a prime (1085564803) 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 in 3 ways as a sum of consecutive naturals, for example, 77540337 + ... + 77540350.

It is an arithmetic number, because the mean of its divisors is an integer number (310161376).

Almost surely, 2^1085564809 is an apocalyptic number.

It is an amenable number.

1085564809 is a deficient number, since it is larger than the sum of its proper divisors (155080695).

1085564809 is an equidigital number, since it uses as much as digits as its factorization.

1085564809 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 155080694.

The product of its (nonzero) digits is 345600, while the sum is 46.

The square root of 1085564809 is about 32947.9105407308. The cubic root of 1085564809 is about 1027.7447147921.

The spelling of 1085564809 in words is "one billion, eighty-five million, five hundred sixty-four thousand, eight hundred nine".