1128421856 has 96 divisors (see below), whose sum is σ = 2430005760. Its totient is φ = 513962496.

The previous prime is 1128421841. The next prime is 1128421891. The reversal of 1128421856 is 6581248211.

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

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 2316845 + ... + 2317331.

It is an arithmetic number, because the mean of its divisors is an integer number (25312560).

Almost surely, 2^1128421856 is an apocalyptic number.

1128421856 is a gapful number since it is divisible by the number (16) 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 1128421856, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1215002880).

1128421856 is an abundant number, since it is smaller than the sum of its proper divisors (1301583904).

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

1128421856 is a wasteful number, since it uses less digits than its factorization.

1128421856 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 656 (or 648 counting only the distinct ones).

The product of its digits is 30720, while the sum is 38.

The square root of 1128421856 is about 33591.9909502250. The cubic root of 1128421856 is about 1041.0953252912.

The spelling of 1128421856 in words is "one billion, one hundred twenty-eight million, four hundred twenty-one thousand, eight hundred fifty-six".