845291009 has 4 divisors (see below), whose sum is σ = 882042816. Its totient is φ = 808539204.

The previous prime is 845290951. The next prime is 845291021. The reversal of 845291009 is 900192548.

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 845291009 - 2¹² = 845286913 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (845291059) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 18375869 + ... + 18375914.

It is an arithmetic number, because the mean of its divisors is an integer number (220510704).

Almost surely, 2^845291009 is an apocalyptic number.

It is an amenable number.

845291009 is a deficient number, since it is larger than the sum of its proper divisors (36751807).

845291009 is a wasteful number, since it uses less digits than its factorization.

845291009 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 36751806.

The product of its (nonzero) digits is 25920, while the sum is 38.

The square root of 845291009 is about 29073.8887835804. Note that the first 3 decimals coincide. The cubic root of 845291009 is about 945.5157115313.

The spelling of 845291009 in words is "eight hundred forty-five million, two hundred ninety-one thousand, nine".