1981840262400 has 432 divisors, whose sum is σ = 7359247033600. Its totient is φ = 521797386240.

The previous prime is 1981840262387. The next prime is 1981840262401. The reversal of 1981840262400 is 42620481891.

1981840262400 is a `hidden beast` number, since 1 + 9 + 8 + 18 + 4 + 0 + 2 + 624 + 0 + 0 = 666.

It is a tau number, because it is divible by the number of its divisors (432).

It is a Harshad number since it is a multiple of its sum of digits (45).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1981840262401) by changing a digit.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 13578612 + ... + 13723788.

Almost surely, 2^{1981840262400} is an apocalyptic number.

1981840262400 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 1981840262400, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (3679623516800).

1981840262400 is an abundant number, since it is smaller than the sum of its proper divisors (5377406771200).

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

1981840262400 is a wasteful number, since it uses less digits than its factorization.

1981840262400 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 145291 (or 145266 counting only the distinct ones).

The product of its (nonzero) digits is 221184, while the sum is 45.

The spelling of 1981840262400 in words is "one trillion, nine hundred eighty-one billion, eight hundred forty million, two hundred sixty-two thousand, four hundred".