20505335328611 has 4 divisors (see below), whose sum is σ = 23434668946992. Its totient is φ = 17576001710232.

The previous prime is 20505335328523. The next prime is 20505335328623. The reversal of 20505335328611 is 11682353350502.

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

It is a de Polignac number, because none of the positive numbers 2^k-20505335328611 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (20505335328641) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1464666809180 + ... + 1464666809193.

It is an arithmetic number, because the mean of its divisors is an integer number (5858667236748).

Almost surely, 2^{20505335328611} is an apocalyptic number.

20505335328611 is a deficient number, since it is larger than the sum of its proper divisors (2929333618381).

20505335328611 is an equidigital number, since it uses as much as digits as its factorization.

20505335328611 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2929333618380.

The product of its (nonzero) digits is 648000, while the sum is 44.

The spelling of 20505335328611 in words is "twenty trillion, five hundred five billion, three hundred thirty-five million, three hundred twenty-eight thousand, six hundred eleven".