20017612805 has 4 divisors (see below), whose sum is σ = 24021135372. Its totient is φ = 16014090240.

The previous prime is 20017612789. The next prime is 20017612843. The reversal of 20017612805 is 50821671002.

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 2194828801 + 17822784004 = 46849^2 + 133502^2 .

It is not a de Polignac number, because 20017612805 - 2⁴ = 20017612789 is a prime.

It is a Duffinian number.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 2001761276 + ... + 2001761285.

It is an arithmetic number, because the mean of its divisors is an integer number (6005283843).

Almost surely, 2^20017612805 is an apocalyptic number.

It is an amenable number.

20017612805 is a deficient number, since it is larger than the sum of its proper divisors (4003522567).

20017612805 is an equidigital number, since it uses as much as digits as its factorization.

20017612805 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4003522566.

The product of its (nonzero) digits is 6720, while the sum is 32.

The spelling of 20017612805 in words is "twenty billion, seventeen million, six hundred twelve thousand, eight hundred five".