1984044090721 has 45 divisors (see below), whose sum is σ = 2540278385505. Its totient is φ = 1545078732120.

The previous prime is 1984044090713. The next prime is 1984044090751. The reversal of 1984044090721 is 1270904404891.

It is a happy number.

The square root of 1984044090721 is 1408561.

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

It is not a de Polignac number, because 1984044090721 - 2³ = 1984044090713 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (49).

It is not an unprimeable number, because it can be changed into a prime (1984044090701) by changing a digit.

It is a polite number, since it can be written in 44 ways as a sum of consecutive naturals, for example, 1193050336 + ... + 1193051998.

It is an arithmetic number, because the mean of its divisors is an integer number (56450630789).

Almost surely, 2^{1984044090721} is an apocalyptic number.

1984044090721 is a gapful number since it is divisible by the number (11) formed by its first and last digit.

1984044090721 is the 1408561-st square number.

1984044090721 is the 704281-st centered octagonal number.

It is an amenable number.

1984044090721 is a deficient number, since it is larger than the sum of its proper divisors (556234294784).

1984044090721 is an frugal number, since it uses more digits than its factorization.

1984044090721 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3384 (or 1681 counting only the distinct ones).

The product of its (nonzero) digits is 580608, while the sum is 49.

Multiplying 1984044090721 by its sum of digits (49), we get a square (97218160445329 = 9859927²).

1984044090721 divided by its sum of digits (49) gives a square (40490695729 = 201223²).

The spelling of 1984044090721 in words is "one trillion, nine hundred eighty-four billion, forty-four million, ninety thousand, seven hundred twenty-one".