1121821428 has 144 divisors (see below), whose sum is σ = 3332031360. Its totient is φ = 286053120.

The previous prime is 1121821417. The next prime is 1121821433. The reversal of 1121821428 is 8241281211.

1121821428 is digitally balanced in base 4, because in such base it contains all the possibile digits an equal number of times.

It is a junction number, because it is equal to n+sod(n) for n = 1121821395 and 1121821404.

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, 1048878 + ... + 1049946.

Almost surely, 2^1121821428 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 1121821428, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1666015680).

1121821428 is an abundant number, since it is smaller than the sum of its proper divisors (2210209932).

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

1121821428 is a wasteful number, since it uses less digits than its factorization.

1121821428 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1158 (or 1125 counting only the distinct ones).

The product of its digits is 2048, while the sum is 30.

The square root of 1121821428 is about 33493.6027921751. The cubic root of 1121821428 is about 1039.0614770252.

The spelling of 1121821428 in words is "one billion, one hundred twenty-one million, eight hundred twenty-one thousand, four hundred twenty-eight".