221004091028 has 24 divisors (see below), whose sum is σ = 451028760000. Its totient is φ = 94716038424.

The previous prime is 221004091013. The next prime is 221004091051. The reversal of 221004091028 is 820190400122.

It is a super-2 number, since 2×221004091028² (a number of 23 digits) contains 22 as substring.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 80539478 + ... + 80542221.

It is an arithmetic number, because the mean of its divisors is an integer number (18792865000).

Almost surely, 2^221004091028 is an apocalyptic number.

221004091028 is a gapful number since it is divisible by the number (28) formed by its first and last digit.

It is an amenable number.

221004091028 is an abundant number, since it is smaller than the sum of its proper divisors (230024668972).

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

221004091028 is a wasteful number, since it uses less digits than its factorization.

221004091028 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 161081724 (or 161081708 counting only the distinct ones).

The product of its (nonzero) digits is 2304, while the sum is 29.

The spelling of 221004091028 in words is "two hundred twenty-one billion, four million, ninety-one thousand, twenty-eight".