1981047257280 has 2016 divisors, whose sum is σ = 9194957683200. Its totient is φ = 392059699200.

The previous prime is 1981047257197. The next prime is 1981047257311. The reversal of 1981047257280 is 827527401891.

1981047257280 is a `hidden beast` number, since 1 + 9 + 8 + 104 + 7 + 257 + 280 = 666.

It is a tau number, because it is divible by the number of its divisors (2016).

It is a super-2 number, since 2×1981047257280² (a number of 25 digits) contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (54).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 287 ways as a sum of consecutive naturals, for example, 19614329230 + ... + 19614329330.

Almost surely, 2^{1981047257280} is an apocalyptic number.

1981047257280 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 1981047257280, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (4597478841600).

1981047257280 is an abundant number, since it is smaller than the sum of its proper divisors (7213910425920).

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

1981047257280 is a wasteful number, since it uses less digits than its factorization.

1981047257280 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 280 (or 150 counting only the distinct ones).

The product of its (nonzero) digits is 2257920, while the sum is 54.

The spelling of 1981047257280 in words is "one trillion, nine hundred eighty-one billion, forty-seven million, two hundred fifty-seven thousand, two hundred eighty".