20910883904065 has 4 divisors (see below), whose sum is σ = 25093060684884. Its totient is φ = 16728707123248.

The previous prime is 20910883904041. The next prime is 20910883904123. The reversal of 20910883904065 is 56040938801902.

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 3010166010289 + 17900717893776 = 1734983^2 + 4230924^2 .

It is a cyclic number.

It is not a de Polignac number, because 20910883904065 - 2³¹ = 20908736420417 is a prime.

It is a super-2 number, since 2×20910883904065² (a number of 27 digits) contains 22 as substring.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 20910883903997 and 20910883904015.

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, 2091088390402 + ... + 2091088390411.

It is an arithmetic number, because the mean of its divisors is an integer number (6273265171221).

Almost surely, 2^{20910883904065} is an apocalyptic number.

It is an amenable number.

20910883904065 is a deficient number, since it is larger than the sum of its proper divisors (4182176780819).

20910883904065 is an equidigital number, since it uses as much as digits as its factorization.

20910883904065 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4182176780818.

The product of its (nonzero) digits is 3732480, while the sum is 55.

The spelling of 20910883904065 in words is "twenty trillion, nine hundred ten billion, eight hundred eighty-three million, nine hundred four thousand, sixty-five".