222121789128 has 108 divisors (see below), whose sum is σ = 611430211665. Its totient is φ = 72847532736.

The previous prime is 222121789079. The next prime is 222121789147. The reversal of 222121789128 is 821987121222.

It is a powerful number, because all its prime factors have an exponent greater than 1 and also an Achilles number because it is not a perfect power.

It can be written as a sum of positive squares in 2 ways, for example, as 220841723844 + 1280065284 = 469938^2 + 35778^2 .

It is an ABA number since it can be written as A⋅B^A, here for A=2, B=333258.

It is an unprimeable number.

It is a polite number, since it can be written in 26 ways as a sum of consecutive naturals, for example, 267939018 + ... + 267939846.

Almost surely, 2^222121789128 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 222121789128

222121789128 is an abundant number, since it is smaller than the sum of its proper divisors (389308422537).

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

222121789128 is an frugal number, since it uses more digits than its factorization.

222121789128 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1804 (or 901 counting only the distinct ones).

The product of its digits is 129024, while the sum is 45.

The spelling of 222121789128 in words is "two hundred twenty-two billion, one hundred twenty-one million, seven hundred eighty-nine thousand, one hundred twenty-eight".