8221661228 has 48 divisors (see below), whose sum is σ = 16596464640. Its totient is φ = 3524472000.

The previous prime is 8221661221. The next prime is 8221661251.

8221661228 is nontrivially palindromic in base 10.

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

It is a junction number, because it is equal to n+sod(n) for n = 8221661191 and 8221661200.

It is not an unprimeable number, because it can be changed into a prime (8221661221) 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, 164378 + ... + 208478.

It is an arithmetic number, because the mean of its divisors is an integer number (345759680).

Almost surely, 2^8221661228 is an apocalyptic number.

It is an amenable number.

8221661228 is an abundant number, since it is smaller than the sum of its proper divisors (8374803412).

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

8221661228 is a wasteful number, since it uses less digits than its factorization.

8221661228 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 44358 (or 44356 counting only the distinct ones).

The product of its digits is 36864, while the sum is 38.

The square root of 8221661228 is about 90673.3766218067. The cubic root of 8221661228 is about 2018.3037444488.

The spelling of 8221661228 in words is "eight billion, two hundred twenty-one million, six hundred sixty-one thousand, two hundred twenty-eight".