1643053722400 has 72 divisors (see below), whose sum is σ = 4014028999764. Its totient is φ = 656742374400.

The previous prime is 1643053722397. The next prime is 1643053722421. The reversal of 1643053722400 is 42273503461.

It can be written as a sum of positive squares in 6 ways, for example, as 1376801850384 + 266251872016 = 1173372^2 + 515996^2 .

It is a self number, because there is not a number n which added to its sum of digits gives 1643053722400.

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 11 ways as a sum of consecutive naturals, for example, 350470 + ... + 1846330.

Almost surely, 2^{1643053722400} is an apocalyptic number.

1643053722400 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 1643053722400, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (2007014499882).

1643053722400 is an abundant number, since it is smaller than the sum of its proper divisors (2370975277364).

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

1643053722400 is a wasteful number, since it uses less digits than its factorization.

1643053722400 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1497254 (or 1497241 counting only the distinct ones).

The product of its (nonzero) digits is 120960, while the sum is 37.

The spelling of 1643053722400 in words is "one trillion, six hundred forty-three billion, fifty-three million, seven hundred twenty-two thousand, four hundred".