1991846774400 has 384 divisors, whose sum is σ = 7504497538560. Its totient is φ = 454877491200.

The previous prime is 1991846774353. The next prime is 1991846774417. The reversal of 1991846774400 is 44776481991.

It is a tau number, because it is divible by the number of its divisors (384).

It is a Harshad number since it is a multiple of its sum of digits (60).

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 79753915 + ... + 79778885.

It is an arithmetic number, because the mean of its divisors is an integer number (19542962340).

Almost surely, 2^{1991846774400} is an apocalyptic number.

1991846774400 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 1991846774400, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (3752248769280).

1991846774400 is an abundant number, since it is smaller than the sum of its proper divisors (5512650764160).

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

1991846774400 is a wasteful number, since it uses less digits than its factorization.

1991846774400 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 26192 (or 26175 counting only the distinct ones).

The product of its (nonzero) digits is 12192768, while the sum is 60.

The spelling of 1991846774400 in words is "one trillion, nine hundred ninety-one billion, eight hundred forty-six million, seven hundred seventy-four thousand, four hundred".