820500090 has 32 divisors (see below), whose sum is σ = 1998596160. Its totient is φ = 215533824.

The previous prime is 820500089. The next prime is 820500097. The reversal of 820500090 is 90005028.

It is a self number, because there is not a number n which added to its sum of digits gives 820500090.

It is not an unprimeable number, because it can be changed into a prime (820500097) 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, 202095 + ... + 206114.

It is an arithmetic number, because the mean of its divisors is an integer number (62456130).

Almost surely, 2^820500090 is an apocalyptic number.

820500090 is an abundant number, since it is smaller than the sum of its proper divisors (1178096070).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

820500090 is a wasteful number, since it uses less digits than its factorization.

820500090 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 408286.

The product of its (nonzero) digits is 720, while the sum is 24.

The square root of 820500090 is about 28644.3727457942. The cubic root of 820500090 is about 936.1803997927.

The spelling of 820500090 in words is "eight hundred twenty million, five hundred thousand, ninety".