20811661256055 has 16 divisors (see below), whose sum is σ = 33299945933184. Its totient is φ = 11099123362080.

The previous prime is 20811661256027. The next prime is 20811661256107. The reversal of 20811661256055 is 55065216611802.

It is not a de Polignac number, because 20811661256055 - 2¹² = 20811661251959 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 20811661255995 and 20811661256013.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 26430801 + ... + 27206810.

It is an arithmetic number, because the mean of its divisors is an integer number (2081246620824).

Almost surely, 2^{20811661256055} is an apocalyptic number.

20811661256055 is a deficient number, since it is larger than the sum of its proper divisors (12488284677129).

20811661256055 is a wasteful number, since it uses less digits than its factorization.

20811661256055 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 53663486.

The product of its (nonzero) digits is 864000, while the sum is 48.

Adding to 20811661256055 its reverse (55065216611802), we get a palindrome (75876877867857).

The spelling of 20811661256055 in words is "twenty trillion, eight hundred eleven billion, six hundred sixty-one million, two hundred fifty-six thousand, fifty-five".