1663800550505 has 4 divisors (see below), whose sum is σ = 1996560660612. Its totient is φ = 1331040440400.

The previous prime is 1663800550459. The next prime is 1663800550547. The reversal of 1663800550505 is 5050550083661.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 261461436889 + 1402339113616 = 511333^2 + 1184204^2 .

It is a de Polignac number, because none of the positive numbers 2^k-1663800550505 is a prime.

It is a Duffinian 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 3 ways as a sum of consecutive naturals, for example, 166380055046 + ... + 166380055055.

It is an arithmetic number, because the mean of its divisors is an integer number (499140165153).

Almost surely, 2^{1663800550505} is an apocalyptic number.

It is an amenable number.

1663800550505 is a deficient number, since it is larger than the sum of its proper divisors (332760110107).

1663800550505 is an equidigital number, since it uses as much as digits as its factorization.

1663800550505 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 332760110106.

The product of its (nonzero) digits is 540000, while the sum is 44.

The spelling of 1663800550505 in words is "one trillion, six hundred sixty-three billion, eight hundred million, five hundred fifty thousand, five hundred five".