1028221920 has 288 divisors, whose sum is σ = 3863583360. Its totient is φ = 246942720.

The previous prime is 1028221913. The next prime is 1028221933. The reversal of 1028221920 is 291228201.

It is a tau number, because it is divible by the number of its divisors (288).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 2201527 + ... + 2201993.

It is an arithmetic number, because the mean of its divisors is an integer number (13415220).

Almost surely, 2^1028221920 is an apocalyptic number.

1028221920 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 1028221920, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1931791680).

1028221920 is an abundant number, since it is smaller than the sum of its proper divisors (2835361440).

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

1028221920 is a wasteful number, since it uses less digits than its factorization.

1028221920 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 638 (or 627 counting only the distinct ones).

The product of its (nonzero) digits is 1152, while the sum is 27.

The square root of 1028221920 is about 32065.8996443262. The cubic root of 1028221920 is about 1009.3201712079.

The spelling of 1028221920 in words is "one billion, twenty-eight million, two hundred twenty-one thousand, nine hundred twenty".