1981112550400 has 297 divisors, whose sum is σ = 5194042576461. Its totient is φ = 749115924480.

The previous prime is 1981112550397. The next prime is 1981112550401. The reversal of 1981112550400 is 40552111891.

It is a happy number.

The square root of 1981112550400 is 1407520.

It is a perfect power (a square), and thus also a powerful number.

It can be written as a sum of positive squares in only one way, i.e., 713200518144 + 1267912032256 = 844512^2 + 1126016^2 .

It is a self number, because there is not a number n which added to its sum of digits gives 1981112550400.

It is not an unprimeable number, because it can be changed into a prime (1981112550401) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 26 ways as a sum of consecutive naturals, for example, 4278860569 + ... + 4278861031.

Almost surely, 2^{1981112550400} is an apocalyptic number.

1981112550400 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

1981112550400 is the 1407520-th square number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 1981112550400

1981112550400 is an abundant number, since it is smaller than the sum of its proper divisors (3212930026061).

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

1981112550400 is an frugal number, since it uses more digits than its factorization.

1981112550400 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 994 (or 489 counting only the distinct ones).

The product of its (nonzero) digits is 14400, while the sum is 37.

The spelling of 1981112550400 in words is "one trillion, nine hundred eighty-one billion, one hundred twelve million, five hundred fifty thousand, four hundred".