221222021028 has 12 divisors (see below), whose sum is σ = 516184715760. Its totient is φ = 73740673672.

The previous prime is 221222021021. The next prime is 221222021029. The reversal of 221222021028 is 820120222122.

It is a happy number.

It is a tau number, because it is divible by the number of its divisors (12).

It is a junction number, because it is equal to n+sod(n) for n = 221222020989 and 221222021007.

It is not an unprimeable number, because it can be changed into a prime (221222021021) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 9217584198 + ... + 9217584221.

It is an arithmetic number, because the mean of its divisors is an integer number (43015392980).

Almost surely, 2^221222021028 is an apocalyptic number.

It is an amenable number.

221222021028 is an abundant number, since it is smaller than the sum of its proper divisors (294962694732).

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

221222021028 is a wasteful number, since it uses less digits than its factorization.

221222021028 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 18435168426 (or 18435168424 counting only the distinct ones).

The product of its (nonzero) digits is 1024, while the sum is 24.

The spelling of 221222021028 in words is "two hundred twenty-one billion, two hundred twenty-two million, twenty-one thousand, twenty-eight".