1994983928721 has 81 divisors (see below), whose sum is σ = 3390168305979. Its totient is φ = 1127194119072.

The previous prime is 1994983928689. The next prime is 1994983928783. The reversal of 1994983928721 is 1278293894991.

It is a happy number.

The square root of 1994983928721 is 1412439.

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

1994983928721 is a `hidden beast` number, since 1 + 9 + 9 + 498 + 39 + 2 + 87 + 21 = 666.

It can be written as a sum of positive squares in only one way, i.e., 464231009025 + 1530752919696 = 681345^2 + 1237236^2 .

It is not a de Polignac number, because 1994983928721 - 2⁵ = 1994983928689 is a prime.

It is a Curzon number.

It is a self number, because there is not a number n which added to its sum of digits gives 1994983928721.

It is not an unprimeable number, because it can be changed into a prime (1994987928721) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 80 ways as a sum of consecutive naturals, for example, 3055105231 + ... + 3055105883.

Almost surely, 2^{1994983928721} is an apocalyptic number.

1994983928721 is the 1412439-th square number.

1994983928721 is the 706220-th centered octagonal number.

It is an amenable number.

1994983928721 is a deficient number, since it is larger than the sum of its proper divisors (1395184377258).

1994983928721 is an frugal number, since it uses more digits than its factorization.

1994983928721 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1532 (or 766 counting only the distinct ones).

The product of its digits is 141087744, while the sum is 72.

The spelling of 1994983928721 in words is "one trillion, nine hundred ninety-four billion, nine hundred eighty-three million, nine hundred twenty-eight thousand, seven hundred twenty-one".