20353518505 has 4 divisors (see below), whose sum is σ = 24424222212. Its totient is φ = 16282814800.

The previous prime is 20353518469. The next prime is 20353518533. The reversal of 20353518505 is 50581535302.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 50581535302 = 2 ⋅25290767651.

It can be written as a sum of positive squares in 2 ways, for example, as 7047434601 + 13306083904 = 83949^2 + 115352^2 .

It is not a de Polignac number, because 20353518505 - 2⁷ = 20353518377 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 (17) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 2035351846 + ... + 2035351855.

It is an arithmetic number, because the mean of its divisors is an integer number (6106055553).

Almost surely, 2^20353518505 is an apocalyptic number.

It is an amenable number.

20353518505 is a deficient number, since it is larger than the sum of its proper divisors (4070703707).

20353518505 is an equidigital number, since it uses as much as digits as its factorization.

20353518505 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4070703706.

The product of its (nonzero) digits is 90000, while the sum is 37.

The spelling of 20353518505 in words is "twenty billion, three hundred fifty-three million, five hundred eighteen thousand, five hundred five".