1643975294976 has 945 divisors, whose sum is σ = 5844576490221. Its totient is φ = 460844826624.

The previous prime is 1643975294963. The next prime is 1643975295007. The reversal of 1643975294976 is 6794925793461.

The square root of 1643975294976 is 1282176.

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

1643975294976 is a `hidden beast` number, since 1 + 6 + 4 + 3 + 9 + 7 + 529 + 4 + 97 + 6 = 666.

It can be written as a sum of positive squares in only one way, i.e., 1185137049600 + 458838245376 = 1088640^2 + 677376^2 .

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

It is an unprimeable number.

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 62 ways as a sum of consecutive naturals, for example, 31018401766 + ... + 31018401818.

Almost surely, 2^{1643975294976} is an apocalyptic number.

1643975294976 is a gapful number since it is divisible by the number (16) formed by its first and last digit.

1643975294976 is the 1282176-th square number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 1643975294976

1643975294976 is an abundant number, since it is smaller than the sum of its proper divisors (4200601195245).

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

1643975294976 is an frugal number, since it uses more digits than its factorization.

1643975294976 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 166 (or 65 counting only the distinct ones).

The product of its digits is 617258880, while the sum is 72.

The spelling of 1643975294976 in words is "one trillion, six hundred forty-three billion, nine hundred seventy-five million, two hundred ninety-four thousand, nine hundred seventy-six".