818855388 has 144 divisors (see below), whose sum is σ = 2484911520. Its totient is φ = 224612352.

The previous prime is 818855383. The next prime is 818855413. The reversal of 818855388 is 883558818.

818855388 is a `hidden beast` number, since 8 + 1 + 8 + 8 + 553 + 88 = 666.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (818855383) by changing a digit.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 148456 + ... + 153872.

It is an arithmetic number, because the mean of its divisors is an integer number (17256330).

Almost surely, 2^818855388 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 818855388, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1242455760).

818855388 is an abundant number, since it is smaller than the sum of its proper divisors (1666056132).

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

818855388 is a wasteful number, since it uses less digits than its factorization.

818855388 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5476 (or 5471 counting only the distinct ones).

The product of its digits is 2457600, while the sum is 54.

The square root of 818855388 is about 28615.6493548548. The cubic root of 818855388 is about 935.5544531904.

The spelling of 818855388 in words is "eight hundred eighteen million, eight hundred fifty-five thousand, three hundred eighty-eight".