820109577 has 16 divisors (see below), whose sum is σ = 1253107712. Its totient is φ = 467352720.

The previous prime is 820109573. The next prime is 820109579. The reversal of 820109577 is 775901028.

It is not a de Polignac number, because 820109577 - 2² = 820109573 is a prime.

It is a Smith number, since the sum of its digits (39) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (820109573) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 45499 + ... + 60912.

It is an arithmetic number, because the mean of its divisors is an integer number (78319232).

Almost surely, 2^820109577 is an apocalyptic number.

It is an amenable number.

820109577 is a deficient number, since it is larger than the sum of its proper divisors (432998135).

820109577 is a wasteful number, since it uses less digits than its factorization.

820109577 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 106788.

The product of its (nonzero) digits is 35280, while the sum is 39.

The square root of 820109577 is about 28637.5553600512. Note that the first 3 decimals coincide. The cubic root of 820109577 is about 936.0318527311.

The spelling of 820109577 in words is "eight hundred twenty million, one hundred nine thousand, five hundred seventy-seven".