20455535431566 has 12 divisors (see below), whose sum is σ = 44320326768432. Its totient is φ = 6818511810516.

The previous prime is 20455535431561. The next prime is 20455535431589. The reversal of 20455535431566 is 66513453555402.

20455535431566 is a `hidden beast` number, since 2 + 0 + 4 + 5 + 5 + 5 + 35 + 43 + 1 + 566 = 666.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20455535431561) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 568209317526 + ... + 568209317561.

It is an arithmetic number, because the mean of its divisors is an integer number (3693360564036).

Almost surely, 2^{20455535431566} is an apocalyptic number.

20455535431566 is an abundant number, since it is smaller than the sum of its proper divisors (23864791336866).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

20455535431566 is a wasteful number, since it uses less digits than its factorization.

20455535431566 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1136418635095 (or 1136418635092 counting only the distinct ones).

The product of its (nonzero) digits is 32400000, while the sum is 54.

Adding to 20455535431566 its reverse (66513453555402), we get a palindrome (86968988986968).

The spelling of 20455535431566 in words is "twenty trillion, four hundred fifty-five billion, five hundred thirty-five million, four hundred thirty-one thousand, five hundred sixty-six".