1981420027776 has 288 divisors, whose sum is σ = 6861356634600. Its totient is φ = 546598176768.

The previous prime is 1981420027753. The next prime is 1981420027781. The reversal of 1981420027776 is 6777200241891.

1981420027776 is a `hidden beast` number, since 1 + 9 + 81 + 420 + 0 + 2 + 77 + 76 = 666.

It is a tau number, because it is divible by the number of its divisors (288).

It is a super-3 number, since 3×1981420027776³ (a number of 38 digits) contains 333 as substring. Note that it is a super-d number also for d = 2.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 35 ways as a sum of consecutive naturals, for example, 1031791 + ... + 2242193.

Almost surely, 2^{1981420027776} is an apocalyptic number.

1981420027776 is a gapful number since it is divisible by the number (16) 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 1981420027776, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (3430678317300).

1981420027776 is an abundant number, since it is smaller than the sum of its proper divisors (4879936606824).

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

1981420027776 is a wasteful number, since it uses less digits than its factorization.

1981420027776 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1210466 (or 1210444 counting only the distinct ones).

The product of its (nonzero) digits is 2370816, while the sum is 54.

The spelling of 1981420027776 in words is "one trillion, nine hundred eighty-one billion, four hundred twenty million, twenty-seven thousand, seven hundred seventy-six".