1228533840 has 120 divisors (see below), whose sum is σ = 4226557608. Its totient is φ = 319610880.

The previous prime is 1228533833. The next prime is 1228533919. The reversal of 1228533840 is 483358221.

1228533840 is a `hidden beast` number, since 1 + 2 + 285 + 338 + 40 = 666.

It can be written as a sum of positive squares in 4 ways, for example, as 211179024 + 1017354816 = 14532^2 + 31896^2 .

It is a tau number, because it is divible by the number of its divisors (120).

It is a Harshad number since it is a multiple of its sum of digits (36).

It is a junction number, because it is equal to n+sod(n) for n = 1228533795 and 1228533804.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 8712 + ... + 50328.

Almost surely, 2^1228533840 is an apocalyptic number.

1228533840 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 1228533840, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (2113278804).

1228533840 is an abundant number, since it is smaller than the sum of its proper divisors (2998023768).

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

1228533840 is a wasteful number, since it uses less digits than its factorization.

1228533840 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 41677 (or 41668 counting only the distinct ones).

The product of its (nonzero) digits is 46080, while the sum is 36.

The square root of 1228533840 is about 35050.4470727550. The cubic root of 1228533840 is about 1071.0153810950.

The spelling of 1228533840 in words is "one billion, two hundred twenty-eight million, five hundred thirty-three thousand, eight hundred forty".