220501809 has 18 divisors (see below), whose sum is σ = 350091378. Its totient is φ = 133636800.

The previous prime is 220501777. The next prime is 220501843. The reversal of 220501809 is 908105022.

It can be written as a sum of positive squares in only one way, i.e., 157251600 + 63250209 = 12540^2 + 7953^2 .

It is not a de Polignac number, because 220501809 - 2⁵ = 220501777 is a prime.

It is a Smith number, since the sum of its digits (27) coincides with the sum of the digits of its prime factors.

It is not an unprimeable number, because it can be changed into a prime (220501009) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 17 ways as a sum of consecutive naturals, for example, 100152 + ... + 102329.

It is an arithmetic number, because the mean of its divisors is an integer number (19449521).

Almost surely, 2^220501809 is an apocalyptic number.

It is an amenable number.

220501809 is a deficient number, since it is larger than the sum of its proper divisors (129589569).

220501809 is a wasteful number, since it uses less digits than its factorization.

220501809 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 202509 (or 202495 counting only the distinct ones).

The product of its (nonzero) digits is 1440, while the sum is 27.

The square root of 220501809 is about 14849.3033169910. The cubic root of 220501809 is about 604.1397139262.

The spelling of 220501809 in words is "two hundred twenty million, five hundred one thousand, eight hundred nine".