1121005781280 has 768 divisors, whose sum is σ = 4907554283520. Its totient is φ = 232179609600.

The previous prime is 1121005781249. The next prime is 1121005781383. The reversal of 1121005781280 is 821875001211.

1121005781280 is a `hidden beast` number, since 1 + 1 + 2 + 1 + 0 + 0 + 578 + 1 + 2 + 80 = 666.

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

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 127 ways as a sum of consecutive naturals, for example, 105441565 + ... + 105452195.

It is an arithmetic number, because the mean of its divisors is an integer number (6390044640).

Almost surely, 2^{1121005781280} is an apocalyptic number.

1121005781280 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 1121005781280, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (2453777141760).

1121005781280 is an abundant number, since it is smaller than the sum of its proper divisors (3786548502240).

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

1121005781280 is a wasteful number, since it uses less digits than its factorization.

1121005781280 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 10990 (or 10976 counting only the distinct ones).

The product of its (nonzero) digits is 8960, while the sum is 36.

The spelling of 1121005781280 in words is "one trillion, one hundred twenty-one billion, five million, seven hundred eighty-one thousand, two hundred eighty".