20988460655 has 4 divisors (see below), whose sum is σ = 25186152792. Its totient is φ = 16790768520.

The previous prime is 20988460583. The next prime is 20988460657. The reversal of 20988460655 is 55606488902.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 55606488902 = 2 ⋅27803244451.

It is not a de Polignac number, because 20988460655 - 2⁸ = 20988460399 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 20988460597 and 20988460606.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20988460657) by changing a digit.

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, 2098846061 + ... + 2098846070.

It is an arithmetic number, because the mean of its divisors is an integer number (6296538198).

Almost surely, 2^20988460655 is an apocalyptic number.

20988460655 is a deficient number, since it is larger than the sum of its proper divisors (4197692137).

20988460655 is an equidigital number, since it uses as much as digits as its factorization.

20988460655 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4197692136.

The product of its (nonzero) digits is 4147200, while the sum is 53.

The spelling of 20988460655 in words is "twenty billion, nine hundred eighty-eight million, four hundred sixty thousand, six hundred fifty-five".