20211556565055 has 16 divisors (see below), whose sum is σ = 32338557675360. Its totient is φ = 10779474444288.

The previous prime is 20211556565047. The next prime is 20211556565113. The reversal of 20211556565055 is 55056565511202.

It is not a de Polignac number, because 20211556565055 - 2³ = 20211556565047 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 20211556564995 and 20211556565013.

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, 8176639 + ... + 10357631.

It is an arithmetic number, because the mean of its divisors is an integer number (2021159854710).

Almost surely, 2^{20211556565055} is an apocalyptic number.

20211556565055 is a deficient number, since it is larger than the sum of its proper divisors (12127001110305).

20211556565055 is a wasteful number, since it uses less digits than its factorization.

20211556565055 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2798810.

The product of its (nonzero) digits is 2250000, while the sum is 48.

The spelling of 20211556565055 in words is "twenty trillion, two hundred eleven billion, five hundred fifty-six million, five hundred sixty-five thousand, fifty-five".