820705009 has 8 divisors (see below), whose sum is σ = 850424960. Its totient is φ = 791468496.

The previous prime is 820704979. The next prime is 820705031. The reversal of 820705009 is 900507028.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 820705009 - 2⁵ = 820704977 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (820705049) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 117402 + ... + 124195.

It is an arithmetic number, because the mean of its divisors is an integer number (106303120).

Almost surely, 2^820705009 is an apocalyptic number.

It is an amenable number.

820705009 is a deficient number, since it is larger than the sum of its proper divisors (29719951).

820705009 is a wasteful number, since it uses less digits than its factorization.

820705009 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 241719.

The product of its (nonzero) digits is 5040, while the sum is 31.

The square root of 820705009 is about 28647.9494728680. The cubic root of 820705009 is about 936.2583299823.

The spelling of 820705009 in words is "eight hundred twenty million, seven hundred five thousand, nine".