1997993558016 has 315 divisors, whose sum is σ = 6005740979721. Its totient is φ = 664369496064.

The previous prime is 1997993557999. The next prime is 1997993558017. The reversal of 1997993558016 is 6108553997991.

The square root of 1997993558016 is 1413504.

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

1997993558016 is a `hidden beast` number, since 1 + 9 + 9 + 7 + 9 + 9 + 35 + 580 + 1 + 6 = 666.

It can be written as a sum of positive squares in only one way, i.e., 1826000879616 + 171992678400 = 1351296^2 + 414720^2 .

It is a Smith number, since the sum of its digits (72) coincides with the sum of the digits of its prime factors.

It is a Harshad number since it is a multiple of its sum of digits (72).

It is not an unprimeable number, because it can be changed into a prime (1997993558017) 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 20 ways as a sum of consecutive naturals, for example, 4885069620 + ... + 4885070028.

Almost surely, 2^{1997993558016} is an apocalyptic number.

1997993558016 is a gapful number since it is divisible by the number (16) formed by its first and last digit.

1997993558016 is the 1413504-th square number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 1997993558016

1997993558016 is an abundant number, since it is smaller than the sum of its proper divisors (4007747421705).

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

1997993558016 is an frugal number, since it uses more digits than its factorization.

1997993558016 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 864 (or 414 counting only the distinct ones).

The product of its (nonzero) digits is 165337200, while the sum is 72.

The spelling of 1997993558016 in words is "one trillion, nine hundred ninety-seven billion, nine hundred ninety-three million, five hundred fifty-eight thousand, sixteen".