1021781507880 has 256 divisors, whose sum is σ = 3521687569920. Its totient is φ = 232322973696.

The previous prime is 1021781507863. The next prime is 1021781507917. The reversal of 1021781507880 is 887051871201.

It is an unprimeable number.

It is a polite number, since it can be written in 63 ways as a sum of consecutive naturals, for example, 284379364 + ... + 284382956.

It is an arithmetic number, because the mean of its divisors is an integer number (13756592070).

Almost surely, 2^{1021781507880} is an apocalyptic number.

1021781507880 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 1021781507880, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1760843784960).

1021781507880 is an abundant number, since it is smaller than the sum of its proper divisors (2499906062040).

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

1021781507880 is a wasteful number, since it uses less digits than its factorization.

1021781507880 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5300 (or 5296 counting only the distinct ones).

The product of its (nonzero) digits is 250880, while the sum is 48.

The spelling of 1021781507880 in words is "one trillion, twenty-one billion, seven hundred eighty-one million, five hundred seven thousand, eight hundred eighty".