809218550 has 48 divisors (see below), whose sum is σ = 1810717440. Its totient is φ = 262841760.

The previous prime is 809218511. The next prime is 809218559. The reversal of 809218550 is 55812908.

It is a Harshad number since it is a multiple of its sum of digits (38).

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (809218559) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 54194 + ... + 67493.

It is an arithmetic number, because the mean of its divisors is an integer number (37723280).

Almost surely, 2^809218550 is an apocalyptic number.

809218550 is an abundant number, since it is smaller than the sum of its proper divisors (1001498890).

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

809218550 is a wasteful number, since it uses less digits than its factorization.

809218550 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 121725 (or 121720 counting only the distinct ones).

The product of its (nonzero) digits is 28800, while the sum is 38.

The square root of 809218550 is about 28446.7669516239. The cubic root of 809218550 is about 931.8698841177.

The spelling of 809218550 in words is "eight hundred nine million, two hundred eighteen thousand, five hundred fifty".