818221138 has 32 divisors (see below), whose sum is σ = 1468575360. Its totient is φ = 334481280.

The previous prime is 818221127. The next prime is 818221177. The reversal of 818221138 is 831122818.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 21558 + ... + 45838.

It is an arithmetic number, because the mean of its divisors is an integer number (45892980).

Almost surely, 2^818221138 is an apocalyptic number.

818221138 is a deficient number, since it is larger than the sum of its proper divisors (650354222).

818221138 is a wasteful number, since it uses less digits than its factorization.

818221138 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 24402.

The product of its digits is 6144, while the sum is 34.

The square root of 818221138 is about 28604.5649853306. The cubic root of 818221138 is about 935.3128441153.

The spelling of 818221138 in words is "eight hundred eighteen million, two hundred twenty-one thousand, one hundred thirty-eight".