20818722905 has 8 divisors (see below), whose sum is σ = 25324693512. Its totient is φ = 16426827648.

The previous prime is 20818722871. The next prime is 20818722923. The reversal of 20818722905 is 50922781802.

It can be written as a sum of positive squares in 4 ways, for example, as 8793187984 + 12025534921 = 93772^2 + 109661^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 20818722905 - 2¹⁰ = 20818721881 is a prime.

It is a Duffinian number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 28518434 + ... + 28519163.

It is an arithmetic number, because the mean of its divisors is an integer number (3165586689).

Almost surely, 2^20818722905 is an apocalyptic number.

It is an amenable number.

20818722905 is a deficient number, since it is larger than the sum of its proper divisors (4505970607).

20818722905 is an equidigital number, since it uses as much as digits as its factorization.

20818722905 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 57037675.

The product of its (nonzero) digits is 161280, while the sum is 44.

The spelling of 20818722905 in words is "twenty billion, eight hundred eighteen million, seven hundred twenty-two thousand, nine hundred five".