1643664134550 has 48 divisors (see below), whose sum is σ = 4076411784912. Its totient is φ = 438297024000.

The previous prime is 1643664134549. The next prime is 1643664134591. The reversal of 1643664134550 is 554314663461.

It is a happy number.

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 1643664134550.

It is a congruent number.

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 23 ways as a sum of consecutive naturals, for example, 5355250 + ... + 5653850.

It is an arithmetic number, because the mean of its divisors is an integer number (84925245519).

Almost surely, 2^{1643664134550} is an apocalyptic number.

1643664134550 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

1643664134550 is an abundant number, since it is smaller than the sum of its proper divisors (2432747650362).

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

1643664134550 is a wasteful number, since it uses less digits than its factorization.

1643664134550 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 335313 (or 335308 counting only the distinct ones).

The product of its (nonzero) digits is 3110400, while the sum is 48.

The spelling of 1643664134550 in words is "one trillion, six hundred forty-three billion, six hundred sixty-four million, one hundred thirty-four thousand, five hundred fifty".