820609511 has 4 divisors (see below), whose sum is σ = 820725312. Its totient is φ = 820493712.

The previous prime is 820609507. The next prime is 820609513. The reversal of 820609511 is 115906028.

820609511 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 820609511 - 2² = 820609507 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (820609513) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 46526 + ... + 61691.

It is an arithmetic number, because the mean of its divisors is an integer number (205181328).

Almost surely, 2^820609511 is an apocalyptic number.

820609511 is a deficient number, since it is larger than the sum of its proper divisors (115801).

820609511 is a wasteful number, since it uses less digits than its factorization.

820609511 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 115800.

The product of its (nonzero) digits is 4320, while the sum is 32.

The square root of 820609511 is about 28646.2826733243. The cubic root of 820609511 is about 936.2220139430. Note that the first 3 decimals are identical.

The spelling of 820609511 in words is "eight hundred twenty million, six hundred nine thousand, five hundred eleven".